Spinach And Mushroom Strata

• 12 ounces crimini or button mushrooms, thinly sliced
• 1 teaspoon butter
• 8 ounces fresh spinach or 1 box frozen, chopped spinach thawed
• 1/3 cup chopped sun-dried tomatoes
• 1/2 cup grated gruyere cheese + extra for sprinkling
• 1/4 cup parmesan cheese + extra for sprinkling
• 5 large eggs
• 1 1/2 cups milk
• 1 teaspoon mustard powder
• 1/8 teaspoon cayenne pepper or more to taste
• 3/4 teaspoon garlic salt
• 1/2 teaspoon black pepper
• 3/4 teaspoon kosher salt, divided
• 4 cups stale italian or sourdough bread, crusts removed, cut into 1/2" cubes

1. In a non stick skillet with a lid, heat over medium high heat until pan is hot. Add sliced mushrooms and 1/4 teaspoon kosher salt to the skillet and stir once or twice. Put the lid on the pan and let the mushrooms give off their liquid for a minute. Continue to check the mushrooms and stir every 30 seconds or so until all of their liquid has been given up and mushrooms are slightly browned. Transfer the mushrooms to a medium bowl.
2. If you're using fresh spinachrnAdd the butter to the pan and saute the fresh spinach until it just wilts. Transfer the spinach to a fine mesh sieve and press on the spinach with the back of a spoon to squeeze out all the excess liquid. Chop the spinach on a cutting board then add it to the mushrooms
3. If you're using frozen spinachrnPlace spinach in a clean dish towel and squeeze out all the liquid and add it to the mushrooms.
4. Toss the sun-dried tomatoes with the spinach and mushrooms, set aside.
5. In a medium bowl whisk together the eggs, milk, mustard powder, cayenne pepper, garlic salt, black pepper and remaining 1/2 teaspoon kosher salt. Stir in the cheeses.
6. Spray a 4-5 cup casserole dish with nonstick spray. Add 1/3 of the bread cubes. Sprinkle with half of the vegetable mixture. Pour 1/3 of the egg and cheese mixture over the vegetables. Top with 1/3 of the bread cubes and the remaining half of the vegetables. Top with the remaining bread and pour the rest of the egg/cheese mixture evenly over the bread.
7. Use your hands to press the bread lightly into the mixture to soak up the egg custard.
8. Top with a sprinkling of gruyere and parmesan cheese. Cover and refrigerate for 8 hours or overnight.
9. Take the strata out of the refrigerator half an hour before you're ready to bake. Preheat the oven to 350 degrees. Bake strata for 45-50 minutes until puffed, browned and bubbly. Let it rest for 10 minutes before serving. This recipe can be doubled.

crimini, butter, fresh spinach, tomatoes, gruyere cheese , parmesan cheese , eggs, milk, mustard powder, cayenne pepper, garlic salt, black pepper, kosher salt, stale italian

Taken from food52.com/recipes/39709-spinach-and-mushroom-strata (may not work)