½cupminced red, yellow or orange bell pepperor a combination
1teaspoonminced fresh thyme leaves
Kosher salt and freshly ground pepperto taste
Preheat the broiler. Heat an 8 to 10-inch skillet over medium high heat. Add 1 tablespoon of the oil and the butter. Add the onions, and sauté for about 3 minutes until they have started to become tender, then add the mushrooms and sauté for 5 minutes, until fairly tender. Add the peppers and sauté for 2 more minutes until they start to become tender. Stir in the thyme.
Beat the eggs, add them to the pan, stirring frequently for two minutes. Lower the heat to medium low and cook for 2 to 3 minutes until the eggs are set on the bottom. Sprinkle the top with the feta.
Transfer to the broiler. Broil for 1 to 2 minutes until the top is set and the frittata is lightly puffed. Serve hot or at room temperature.