Name: Spinach and Mushroom Strata
Prep time: 15 min
Cook time: 60 min
Total time: 75 min
Ingredients: 10 ounces day-old or stale whole grain bread cut into ¾-inch pieces ((about 8 cups)); 2 tablespoons olive oil; ¼ cup chopped shallots; 10 ounces cremini mushrooms, (sliced); 1 box (10 ounces) frozen chopped spinach, (defrosted and squeezed dry); ¾ teaspoon dried thyme ((or 1 tablespoon fresh)); 1 teaspoon salt, (divided); ½ teaspoon pepper, (divided); 8 large eggs; 2 cups 2% or whole milk; 1 tablespoon Dijon mustard; 3 ounces grated Gruyere cheese, (divided)

Published: Oct 11, 2014 · Last Updated: Jan 2, 2023 by Dr. Sonali Ruder · This post may contain affiliate links · 17 Comments

What Is A Strata?

A strata is a layered casserole made with cubed bread, eggs, cheese and other ingredients like vegetables or meat. It’s like a casserole or savory bread pudding and is definitely a comfort food.

The beauty of making a strata is that you can toss in whatever ingredients you have on hand in your fridge or pantry. Pretty much any veggies work well in a strata like onions, bell peppers, zucchini, and butternut squash. You can also use meat like diced chicken, turkey or sausage. My favorite combination is spinach and mushrooms.

A strata is also the perfect make-ahead dish! You can prepare this spinach and mushroom egg casserole the night before. Then in the morning, simply pop it in the oven and you're good to go!

Why This Strata is Healthier

A traditional strata is a very rich dish with large amounts of butter, cream, and cheese. However to make my spinach and mushroom strata healthier, I use olive oil, reduced fat milk, and a lot less cheese. Gruyere is a strong cheese so a little goes a long way.

For this healthy strata, I also like to use whole grain bread to incorporate healthy whole grains into the dish. Whole grains have high amounts of fiber, vitamins, minerals and antioxidants, which help reduce your risk of chronic disease. Read my post Everything You Need To Know About Whole Grains.

Day-old or stale bread works best to soak up all the custard. I often use a loaf of bread from my local bakery and leave it out overnight.

How To Make Spinach and Mushroom Strata

These are the basic steps for making any strata:

Step 1- Cut the bread into cubes and place them in a large bowl.

Step 2- Sauté your veggies in a skillet with some olive oil. Add any seasonings. Add the mixture to the bowl with the cubed bread and toss to mix everything together.

Step 3- Make the egg custard by whisking eggs, milk, seasonings, and grated cheese.

Step 4- Transfer the bread mixture to a greased baking dish and pour the egg custard on top. Press down on the bread to submerge it all in the liquid.

Step 5- Bake in the oven at 350°F for 50-60 minutes until puffed up and golden brown.

How To Serve This Dish

You can serve this spinach and mushroom strata in a large casserole dish. It's an elegant looking dish that's perfect when you have guests over.

You can also bake this spinach and mushroom strata in individual portions in a muffin pan. That way, you can have a convenient and healthy grab-and-go breakfast any day of the week!