Summer Squash Frittata

3 tablespoons butter 2 small zucchini , chopped into 1/2 inch cubes (about 2 cups) 2 small summer squash, chopped into 1/2 inch cubes (about 2 cups) 1 small[...]

3 tablespoons butter 1 zucchini , cubed 1 yellow squash, cubed 1 small onion , chopped 4 ounces sliced mushrooms 1 (4 ounce) can sliced black olives 8 ounces[...]