Creating a Spinach Frittata can be straightforward when you follow these easy steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Sauté Vegetables: In a medium oven-safe skillet, heat the olive oil over medium heat. Add the chopped onion and bell pepper. Sauté for about 3-5 minutes until they soften.
3. Add Spinach: Incorporate the chopped spinach into the skillet. Cook until wilted, about 2-3 minutes, stirring occasionally.
4. Prepare Egg Mixture: In a separate bowl, whisk together the eggs, milk, salt, and pepper until well combined.
5. Combine Ingredients: Pour the egg mixture over the sautéed vegetables in the skillet. If desired, sprinkle cheese on top for added flavor.
6. Cook on Stovetop: Cook the frittata on the stovetop for 3-4 minutes until the edges begin to set.
7. Bake in Oven: Transfer the skillet to the preheated oven. Bake for 15-20 minutes until the frittata is fully set and lightly golden on top. A toothpick inserted in the center should come out clean.