Preheat the Oven: Preheat your oven to 375°F (190°C), ensuring it reaches the correct temperature for a perfect bake.

Prepare the Vegetables: Heat olive oil in a large skillet over medium heat.

Add the diced onions and red bell peppers, sautéing until they are soft and translucent, about 5 minutes.

Add the minced garlic and cook for an additional minute until fragrant.

Cook the Spinach: Gradually add the chopped spinach to the skillet. Stir continuously until the spinach is wilted and reduced, about 3-4 minutes.

Season with salt and pepper to taste.

Whisk the Eggs: In a large bowl, crack the eggs and whisk them until fully combined. You can add a splash of milk or cream for a richer texture if desired.

Combine Ingredients: Remove the skillet from heat and let the vegetable mixture cool slightly.

Once cooled, add the vegetable mixture to the whisked eggs, ensuring that the ingredients are well mixed.

Bake the Casserole: Pour the egg and vegetable mixture into a greased baking dish.

Place in the oven and bake for 20-25 minutes, or until the eggs are set and the top is slightly golden.

Serve: Let the casserole cool for a few minutes before cutting into it.

Serve warm, with optional toppings like shredded cheese, chopped fresh herbs, or a light drizzle of hot sauce for an extra kick.