Preheat your oven to 350°F (175°C). While the oven is heating, grease a 9x13-inch baking dish with butter or cooking spray. This ensures that your casserole doesn’t stick and makes for an easy cleanup.

If you’re adding meat, like sausage, bacon, or ham, start by cooking it in a skillet over medium heat. This will add extra flavor and texture to your casserole. Drain any excess fat and set aside. If you’re skipping the meat for a vegetarian version, feel free to use your favorite vegetables instead!

In a large bowl, crack 6 large eggs. Whisk them together until well-beaten. Add 1 cup of milk (you can use any milk, but almond or oat milk works well for a dairy-free version). For extra creaminess, add a small amount of sour cream or cream cheese.

Stir in 1 ½ cups of shredded cheese—cheddar is the most common choice, but you can experiment with other cheeses like mozzarella or pepper jack for different flavors. This adds richness and makes your casserole wonderfully cheesy.

Now comes the fun part—layering! Start by adding your cooked protein or vegetables to the bottom of the baking dish. Then, pour the egg mixture over the top, making sure everything is well-distributed. For a little extra flavor, sprinkle in some chopped onions, bell peppers, and herbs like parsley or thyme.

If you want that traditional casserole feel, you can add gluten-free bread cubes. Simply cut up the bread and scatter it throughout the casserole. It’ll absorb the egg mixture and become soft and delicious when baked.

Bake your casserole for 40-45 minutes, or until the top is golden brown and a knife inserted into the center comes out clean. Let it cool for a few minutes before slicing and serving.