Ham and Mushroom Strata

There are very few things I cherish more as a busy parent in charge of meal times, particularly holiday meals, than a good make ahead dish. Especially one that comes together as quickly as this one does. In well under an hour I’ve got this pan fully assembled and chilling in the fridge, so I can move on with my day and continue to check other things off of the seemingly never-ending list.

This strata recipe is cheesy, savory, filling, and simple to throw together. The saltiness of the ham, aromatics of the thyme, and earthiness of the mushrooms come together in a beautiful medley that’s hard to beat. It’s the perfect addition to an Easter brunch, or a good savory option if you’re trying to have an indulgent breakfast ready to go on Christmas morning.

It’s also easily customizable. Have a picky eater who shudders at the mere thought of a mushroom? Try replacing them with a different vegetable, like broccoli, cauliflower, asparagus, or potatoes! Hosting someone who doesn’t eat pork? Substitute the ham for turkey breakfast sausage or bacon, or a vegetarian sausage. Play around until you’ve found a combination that works for your family.

FAQs and Science

Why pre-cook the vegetables before assembling everything? It seems like it would save so much more time to add them raw!

Most vegetables have a fairly high water content. If you don’t pre-cook them and get most of that water out, it still has to go somewhere. That place will be into your strata once they heat up in the oven, leaving you with a sad, watery mess. Plus, browned mushrooms are much, much tastier!

Can I use pre-shredded cheese rather than shredding it myself from a block?

As a fellow hater of hand shredding, I completely get this question. Will it ruin the dish for you to use the pre-shredded stuff? No. Will it make for a slightly better end dish if you shred it by hand, due to no anti-caking agents interfering with how it melts? Yes. If saving a bit of time and dirty dishes matters more, use the stuff in the bag!

What is a high heat rubber spatula?

A high heat rubber spatula is exactly what it sounds like, a rubber spatula that’s designed to handle high temperatures, typically ranging from 350-500F. If you don’t own one, use whichever your favorite tool to saute your vegetables on the stove top is.

Why did you use both olive oil and butter? It seems like overkill.

That’s a tip I learned from Julia Child for cooking mushrooms, and once I tried it, I never looked back. They ended up so much better than when cooked solely with olive oil. Trust me, use both.

Could I use just milk, or a lower fat cream rather than heavy cream?

This strata is meant to be a rich dish. That richness comes from the fat content in the heavy cream and whole milk. It wont completely ruin the dish to use say, 2% milk and light cream, but the flavor and mouthfeel wont be the same. 

I only have dried thyme and pre-ground nutmeg, is that okay to use?

Yes, the flavor wont have as much impact but I’m all for just using what you’ve got when you can.

What You’ll Need

• 9×13 in baking dish
• Plastic wrap
• Large mixing bowl
• Large saute pan
• Chef’s knife
• Serrated knife
• Cutting board
• Cheese grater
• Liquid measuring cup
• Measuring spoons
• Whisk
• High heat rubber spatula
• Microplane

The Process

You’re going to start with all of the prep work, aka mise en place. This is the key to taking the overwhelming stress out of any cooking or baking project: make sure you’ve got all of your supplies and ingredients ready to go before anything else. That way, you’re not scrambling to chop up that onion while the mushrooms hopefully aren’t burning and who used up the mustard and you could’ve sworn you had enough eggs. Take a breath, and just get it all ready to go now when the stakes of taking your time are very low.

Get the baking dish sprayed or buttered down, and set it aside for when you need it at the end. Grab the chef’s knife and cutting board, slice the mushrooms ⅛ in and set them aside.

Finely dice the onions. They aren’t the star of today’s show, they’re just a supportive, flavorful character. Set them aside for now. Thinly slice the scallions, placing the whites in with the onions but keeping the greens separate. They’ll be used as a garnish near the end.

Time to add some heat! Place your saute pan over medium heat, and give it a minute to warm up. Preheating the pan you cook in before adding any oil will help prevent the food you’re cooking from sticking. Add 2 Tablespoons of butter and 2 Tablespoons of olive oil to the hot pan.

Toss in the mushrooms and a large pinch of salt, stirring them with a high heat rubber spatula to coat them. Only stir them occasionally at this point, to allow them to cook out all of the moisture and get the browning they deserve. This will take around 10 minutes or so.

You may have heard that to cook mushrooms, you have to do it in batches or they wont brown. This isn’t true, it will just take a little longer to brown them doing it in one big batch like this. If you leave them alone to release their moisture and get that direct contact with the bottom of the pan for a few minutes in between stirring, they’ll brown just fine. However, if it makes you more comfortable, you’re free to cook them half at a time, using 1 Tablespoon of oil and butter per batch.

Add in the diced onions, the scallion whites, and another pinch of salt, and stir them with the high heat spatula. Allow them to sit and cook, stirring occasionally to sweat them until the onions are translucent, approximately 2-3 minutes.

Set the pan of vegetables aside to cool, either on the counter or in the fridge to really speed up the process. While they cool, cube the loaf of challah and the deli ham.

Grab the large mixing bowl to make the custard. Pour in the whole milk, heavy cream, all 8 eggs, dijon mustard, fresh thyme, salt, and nutmeg. It’s better to freshly grind the nutmeg using a microplane directly into the bowl, for a more aromatic flavor in the final dish. Whisk them all together until you have a homogeneous custard, and set the bowl aside.

Once the vegetables have fully cooled, grate in 2/3 of the cheddar and toss in the ham. Fold it all together until everything is equally distributed.

Onto assembling your strata! Grab the prepared baking dish, and begin the layering process. You’re going to alternate between the cubes of challah and the ham and mushroom filling. Start with ⅓ of the challah you’ve cut up on the bottom, and spread on ½ of the filling. Then another ⅓ of the challah, and the other ½ of the filling. Top that with the final ⅓ of challah cubes.

Carefully, take your custard and pour it over the layered strata. Make sure not to leave any dry spots of bread, or they may not soak up the custard while resting in the fridge and may burn in the oven.

Grate and sprinkle the remaining cheddar over the top of the strata, then sprinkle it with some of the green scallions you sliced earlier. Cover the top of the dish tightly with plastic wrap, and place it in the refrigerator for a minimum of 1 hour, or up to 24 hours ahead of time.

Preheat your oven to 325F, on a convection setting if it’s an option your oven offers. Remove the plastic from the top of your strata, and bake it for 1 hour. Raise the temperature to 375F, leaving the pan in the oven, and bake it for another 15 minutes, or until the top of your strata is a nice golden brown.

Sprinkle the rest of the green scallions on top. Allow the strata to rest for a minimum of 10 minutes so everything has the chance to set up a bit more as it cools, and enjoy! Keep it stored refrigerated in an airtight container for up to 4 days.

Ham and Mushroom Strata

Bake Time: 325F for 60 minutes, 375F for 15 minutes
Servings: 10 servings
Total Time: 3 hours
Prep Time: 45 Minutes

Ingredients

• 15 oz loaf of challah bread

Filling:

• 12 oz portabella or button mushrooms, sliced
• 2 Tablespoons unsalted butter
• 3 Tablespoons olive oil, divided
• Salt, to taste
• 1 cup yellow onion, fine diced
• 3 large scallions, whites and greens divided
• ⅔ lb deli ham
• 8 oz block cheddar (or cheese of choice)

Custard:

• 8 large eggs
• 1 cup heavy cream
• 1 1/2 whole milk
• 4 Tablespoons dijon mustard
• 2 Tablespoons fresh thyme
• 1 1/4 teaspoon salt
• 1/4 teaspoon freshly ground nutmeg

Instructions:

1. Prepare a 9×13 baking dish by either coating it in a nonstick spray or brushing it all over with melted butter. Set this pan aside.
2. Prepare the filling. Slice the mushrooms around 1/8 inch thick, set them aside. Finely dice the onion, set them aside as well. Thinly slice the scallions, placing the whites with the onions and the greens in their own small dish. Cut the deli ham into 1-inch pieces, shred the cheddar into a medium bowl, cube the loaf of challah into 1-inch chunks using the serrated knife, set all of them aside.
3. Heat a large saute pan over medium heat. When the pan is hot, add in 2 Tablespoons of olive oil, 2 Tablespoons of butter, and all of the sliced mushrooms. Sprinkle a large pinch of salt over the mushrooms, stir them using a high heat rubber spatula to coat in the butter and oil. Allow them to sit and cook until they’re golden brown, only stirring occasionally. This should take around 10 minutes.
4. Toss in the diced onion, the scallion whites, and another big pinch of salt. Stir everything together, then stir occasionally while it cooks until the onions are translucent, about 2-3 minutes. Set the vegetables aside to cool.
5. While they cool, cut the challah into 1-inch cubes and largely dice the ham.
6. In a large mixing bowl, add in the eggs, heavy cream, whole milk, dijon mustard, thyme, salt, and freshly ground nutmeg. Whisk until it all comes together in one homogeneous mixture, and set it aside.
7. When the vegetables have fully cooled, add the prepared ham and ⅔ of the shredded cheddar, stir them all together.
8. Grab the prepared baking dish, and sprinkle ⅓ of your cubed challah loaf. Cover the bread with ½ of the mushroom filling, and keep alternating between the challah and the filling, ending on the challah.
9. Carefully, pour the custard over the filling, being sure not to leave any dry spots. Grate the remaining ⅓ of cheddar on top and sprinkle half of the green scallions. Cover the pan in plastic wrap, and chill it in the fridge for a minimum of 1 hour or up to a day ahead of time.
10. Preheat the oven to 325F. Remove the plastic wrap on top of the pan, and bake it for 1 hour. At the 1 hour mark, raise the oven temperature to 375 and bake it for an additional 15 minutes or so, until the top is golden brown. Sprinkle on the remaining green scallions for garnish. Allow it to rest for a minimum of 10 minutes, and enjoy! Refrigerate any leftovers in an airtight container for up to 4 days.

Tips

• This strata can be frozen fully assembled for up to 3 months and baked fresh. Follow the recipe through step 9, using a freezer safe pan and making sure the custard has had a minimum of 4 hours to soak in. Wrap the pan in plastic wrap and then aluminum foil before placing on a flat surface in the freezer. Place it in a 325F oven for 80 minutes, then raise the temperature to 375F until the top has browned.
• If you’ve used a disposable pan for the strata, place it on a sturdy baking sheet before popping it in the oven. This makes it much easier to both toss in and especially remove from the oven.