This Spinach and Mushroom Strata is the perfect way to use up leftover sandwich crust, stale bread, or loaf ends. It’s packed with flavor and the perfect way to start your day.
If you have kids, or even if you were a kid or teenager in the early 2000’s, you know what an “uncrustable” sandwich is. A peanut butter and jelly sandwich cut into a circle with the crusts cut off, sealed in a little plastic bag. Convenience food at its finest.
Well, these days, there are contraptions for making your own crust-free circle sandwiches at home (this is the one I have). And while my kids don’t particularly mind eating sandwich crust, there is another benefit to these sandwiches which is that the edges are sealed shut. And that makes it easy to stack and freeze a bunch of them.
So this year, instead of making PB&J sandwiches every single night and then cleaning up the mess, I’ve been making crustless circle sandwiches in big batches and freezing them. That way I just have to grab them out of the freezer and plop them in the lunch boxes. But it’s cheaper and healthier than the pre-made store-bought ones!
However, there’s one big problem. SO much leftover crust. And for someone who doesn’t like to be wasteful, seeing that big pile of bread crusts hurts.
In the past, I’ve made this Leftover Sandwich Crust Peanut Butter French Toast Casserole, and that’s always a hit. But you can only eat the same thing so many times (unless you’re my kids who will eat some variation of PB&J every single day if given the option).
Something savory sounded good, and so was born this Spinach and Mushroom Leftover Sandwich Crust Strata. It’s packed with spinach, mushrooms, garlic, and sun-dried tomatoes (if you still have garden tomatoes check out how to make your own sun-dried tomatoes). Plus plenty of delicious cheese!
This recipe is the perfect way to use up leftover sandwich crusts. Whenever I make a batch of sandwiches now, I will dice the crusts and pop them in a bag in the freezer to use whenever I’m ready to make a strata.
This recipe is also great if you are the type of family that doesn’t like to eat the bread ends! Just dice them up and keep them in the freezer until you have enough. Stale bread is also perfect. You can use any kind of bread— it can be sandwich bread, but Italian bread, rolls, or even bagels would work too. It’s a great way to reduce waste.
I love this recipe as is, but it’s pretty versatile. You can mix up the types of veggies or cheese you use, or even add some different spices.
What you need to make Spinach and Mushroom Leftover Sandwich Crust Strata:
- Leftover sandwich crusts, bread ends, or stale bread.
- Veggies – I use mushrooms, spinach, and sun-dried tomatoes but you could swap in peppers, onions, kale, etc.
- Eggs and milk – use non-dairy milk or egg substitutes if preferred.
- Cheese – A cheddar-gruyere is great in here— I’ve found it at both Trader Joe’s and a regular grocery store. But if you can’t find it, a sharp cheddar or plain gruyere would work well too.
- Spices – I like to keep it simple with dry mustard, garlic powder, and a touch of spice, but you can add any spices you love!
This Spinach and Mushroom Strata is perfect for meal-prepping. Make it over the weekend and you can enjoy it for breakfast all week long. It also makes a great lunch or dinner. Try pairing it with some bacon and fresh fruit!
- 2 tsp olive oil, divided
- 16 ounces baby bella mushrooms, sliced
- 2 cloves fresh garlic, minced
- 10 oz fresh baby spinach, roughly chopped
- ½ cup sun-dried tomatoes, chopped
- 5 large eggs
- 1½ cups milk
- 1 tsp dry mustard
- 1 tsp garlic powder
- ¼ tsp cayenne pepper (optional)
- ½ tsp salt
- ½ tsp fresh ground black pepper
- 1 cup shredded gruyere-cheddar cheese (or sharp cheddar or gruyere)
- ¼ cup shredded parmesan cheese
- 6 cups leftover sandwich crusts or bread ends, diced into ½-inch cubes
- Heat 1 tsp of olive oil in a large pan over medium heat. Add the sliced mushrooms and saute until all of the water has been released and they are beginning to brown. Transfer to a bowl.
- Add another 1 tsp to the pan and add the garlic. Cook over medium heat for about a minute and then add the spinach. Continue cooking, stirring frequently, until spinach is fully wilted. Cool spinach until you can handle it, then use your hands to squeeze out any excess water. Transfer to the bowl with the mushrooms.
- Add the sun-dried tomatoes to the bowl with the spinach and mushrooms, and stir everything to evenly combine.
- Spray a 9x13-inch baking dish or casserole with nonstick spray and set aside.
- In a large bowl, whisk together eggs, milk, dry mustard, garlic powder, cayenne, salt, and pepper. Stir in cheeses, reserving a bit for sprinkling on top.
- Add half of the bread cubes to the baking dish. Top with half of the vegetables, using your hands to spread them somewhat evenly. Use a ladle or large spoon to top with half of the egg and cheese mixture.
- Repeat with the remaining bread cubes, vegetables, and egg mixture.
- Use your hands to press down the bread and make sure everything is fully immersed in the egg mix.
- Sprinkle remaining cheese on top.
- Cover and refrigerate for 8 hours or overnight.
- When you are ready to bake the strata, take it out of the fridge and let it sit for 20 to 30 minutes.
- Preheat the oven to 350 degrees.
- Bake, uncovered, for 45 minutes until the top is nicely browned. Let cool 10 minutes and then serve.
Check out some other delicious savory breakfast recipes!