Feta Cheese Basil And Tomato Quiche Recipe

– 1 uncooked refrigerated pie crust – 2 tablespoons butter – 1/2 cup finely chopped onion – 1 cup quartered cherry and grape tomatoes – 1 small container, 4 oz, crumbled feta cheese – 1/3 cup chopped fresh basil – 6 eggs – 1/2 cup milk – 1 teaspoon dry oregano – 1 teaspoon salt – 1/4 teaspoon ground black pepper