Preheat the Oven: First, preheat your oven to 375°F. Meanwhile, prepare your ingredients on the counter for an organized cooking process.
Prepare the Egg Mixture: In a large bowl, whisk the eggs with low-fat milk until fully combined. Then, stir in salt, pepper, cumin, and paprika to add a warm, subtle spice.
Sauté Vegetables: Next, heat a non-stick skillet over medium heat. Add a small amount of olive oil and toss in the chopped onions and garlic. Sauté until the onions become translucent, about 3 to 4 minutes. Afterwards, add the diced red and yellow bell peppers along with the chopped spinach. Sauté for an additional 2 minutes until the vegetables are tender.
Combine Ingredients: In a large mixing bowl, combine the sautéed vegetables, diced Hatch green chilies, and whole-grain bread cubes. Then, pour in the egg mixture and gently fold in the shredded cheddar cheese and chopped cilantro. Make sure everything is evenly mixed to ensure every bite is packed with flavor.
Bake the Casserole: Next, spray a lightly greased baking dish with cooking spray. Pour the entire mixture into the dish, ensuring it is spread evenly. Then, place it in the preheated oven and bake for 30 to 35 minutes. The casserole is done when the eggs are fully set and the top is slightly golden.
Cool and Serve: After baking, take the dish out of the oven and let it sit for a few minutes to cool. This resting time allows the flavors to meld perfectly. Finally, slice and serve your delicious green chili egg casserole warm.