Things You'll Need
2 tablespoons olive oil
1 garlic clove, roughly chopped
1 large brown onion, sliced
4 cups button mushrooms, quartered or slivered
1 large bunch or 6 cups spinach, kale or chard, stems removed, washed, dried and roughly chopped
6 large eggs
1 1/2 cups whole milk
1/2 cup heavy cream
1 tablespoon Dijon mustard
1/4 teaspoon ground nutmeg
6 cups bread, cubed
1 cup cheddar cheese, grated
1 cup Parmesan cheese, grated
Salt and pepper
Step 1: Measure and Prepare Your Ingredients
Begin by preparing all your ingredients. Generously butter or oil a 9-inch baking dish and set aside.
Step 2: Cook the Onion and Garlic
Heat the olive oil in a large heavy sauté pan over medium heat and add the garlic and onion. Cook, stirring occasionally, until the onion has slightly softened.
Step 3: Add the Mushrooms
Add the mushrooms to the pan and continue to cook until they just begin to brown.
Step 4: Add the Greens
Add the greens to the pan, season and cook until they just begin to wilt, a few minutes. Set the pan aside and turn off the heat.
Step 5: Mix the Liquid Ingredients
In a large bowl, whisk together the eggs, milk, cream, mustard and nutmeg. Season with salt and pepper.
Step 6: Assemble All the Ingredients Together
To assemble the strata, spread half of the bread over the bottom of the baking dish. Top with mushroom and greens then sprinkle the remaining bread and half the cheeses evenly over the top. Carefully pour the egg mixture over everything and sprinkle with remaining cheese. Season with salt and pepper.
Step 7: Set Aside
Cover tightly with plastic wrap and refrigerate overnight, or for at least 6 hours to absorb.
Step 8: Bake
Take the strata out of the refrigerator 30 minutes before baking and let it sit to room temperature. Preheat the oven to 350 F, uncover the strata and bake it for about 45 minutes or until golden brown and cooked through.
Step 9: Let Cool
Let the strata cool for 10 minutes.
Step 10: Serve!
Serve and enjoy your delicious strata!