2 tablespoons olive oil
1 red pepper, chopped
1 green pepper, chopped
1/4 yellow onion, chopped
1 teaspoon kosher salt
1 teaspoon black pepper
8 egg whites (either separated or in a carton)
1/2 cup feta cheese, crumbled
2 cups fresh spinach
- Preheat the oven to 375°F.
- In a heavy skillet, add olive oil and bring to medium-low heat.
- Saute onions and peppers until vegetables are tender, about 7 minutes.
- Sprinkle the mixture with salt and pepper.
- Pour egg whites into the skillet and cook for 3 minutes.
- Sprinkle the top with feta and spinach.
- Put skillet in oven and bake, uncovered, for 8 to 10 minutes. (If you use whole eggs instead of egg whites, bake at 400°F.)
- Loosen the edges of the frittata with a rubber spatula, and then invert onto a plate.
Source: Calorie Count 
- Makes 2 large servings
- Calories per serving