1/2 cup chopped onion
1/2 cup chopped zucchini
2 ounces cooked mushrooms
1 1/4 ounces shredded cheddar cheese
1 cup milk
2 tablespoons sour-cream
2 eggs (or 3 egg whites)
3/4 cup buttermilk baking mix
Preheat oven to 350°. Spray 9" pie plate with non-stick spray. Spray skillet with non-stick spray; add onion, zucchini and ham. Cook about 2 minutes until onions are translucent.
Spread onion mixture over bottom of pie plate. Sprinkle cheese on top.
In bowl, combine the rest of the ingredients and blend with fork. Pour into pie plate. Bake until golden brown and puffy (35-45 minutes).