This spinach feta egg casserole comes together with wilted spinach, mozzarella, and feta baked into a rich, custardy egg base. It's simple enough for a weekday breakfast and substantial enough to serve a crowd for a holiday brunch.
Spray a 9x13 baking dish with a non-stick cooking spray.
Heat the olive oil over medium-high heat in a large non-stick skillet that has high sides.
Add the greens. Use a spatula to consistently turn the greens over until they are wilted.
Place the greens into the baking dish.
Cut the mozzarella cheese into cubes and place in a medium bowl.
Add the crumbled feta and the green onions.
Add the Spike seasoning and black pepper. Toss to combine.
Place the mixture on top of the greens in the baking dish.
Beat the eggs with the milk until combined and well-whipped. Pour over the cheese.
Use a fork or spoon to move the mixture around gently combining all the ingredients.
Bake for 40-45 minutes or until the mixture is completely set and a knife poked into the center comes out clean. The top should be lightly browned.
Serve hot.
Notes
Milk, water, or plant-based milk all work here. I tested this, and milk gives the eggs a slightly richer texture. For a fluffier, more custard-like result, add an extra half cup of milk to the eggs.You can assemble this the night before and bake it the next morning. It's also fully make-ahead once baked: store in the refrigerator for up to a week in an airtight container.This casserole freezes well, baked or unbaked. Bake, cool completely, wrap tightly, and freeze up to two months. Unbaked, assemble everything except the final bake, cover tightly, and freeze up to two months, then thaw overnight in the fridge before baking.Want individual portions? Pour the mixture into a muffin tin instead, filling each cup three-quarters full. Bake at the same temperature for about 25 minutes, checking for doneness with a toothpick.Don't be shy with the cheese. The cheesier this gets, the better it is.