Ham, Cheese, and Mushroom Strata

Ingredients

• 0.5 teaspoon pepper black as needed freshly ground plus more
• 12 ounces finely-chopped ham cooked trimmed cut into 1/2-inch dice
• 1 pound crimini mushrooms trimmed quartered
• 0.3 cup dijon mustard 
• 1 teaspoon thyme dried
• 12 large eggs 
• 3.5 ounces gruyere cheese shredded
• 8 ounces bread crumbs french italian cut into 3/4-inch cubes ( 6 cups)
• 0.8 teaspoon kosher salt as needed plus more
• 1 cup onion yellow
• 3 tablespoons butter unsalted
• 2.5 cups milk whole

Equipment

• bowl
• frying pan
• oven
• whisk
• wire rack
• plastic wrap
• baking pan
• toothpicks
• aluminum foil

Directions

1. Melt the butter in a large frying pan over medium heat, add the onion, season with salt and pepper, and cook until softened, about 6 minutes.
2. Add the mushrooms and thyme and cook, stirring rarely, until the mushrooms are lightly browned in spots and all of the moisture has evaporated, about 10 minutes.
3. Remove the pan from the heat.
4. Place the eggs in a large bowl and whisk until they’re broken up.
5. Add the milk, mustard, and measured salt and pepper and whisk to combine.
6. Add the ham, bread, cheese, and sautéed mushroom mixture and stir to combine.
7. Pour into a 13-by-9-inch baking dish and arrange into an even layer. Cover the dish with plastic wrap or aluminum foil and refrigerate overnight.
8. Heat the oven to 350°F and arrange a rack in the middle. Meanwhile, remove the strata from the refrigerator and let it sit at room temperature.
9. Remove the plastic wrap or aluminum foil from the strata and bake until a toothpick inserted into the center comes out clean, about 1 hour.
10. Remove the dish to a wire rack and let it cool for 10 minutes before serving.