MellowBellies Frittata

Serves 4 to 6 for dinner
Preheat oven to 325 degrees. Lightly grease a glass pie plate or baking dish.
Wash greens and with water still clinging to the leaves, put the leaves in a two-quart heatproof measuring cup. Cover with a small square of waxed paper, pushed down to form a sort of lid. Put in microwave and heat at full power for about 4 minutes or until leaves have steamed and completely wilted. Drain off any water and set aside.
In a large skillet, heat olive oil and sauté onions until just translucent. Add sausage if using and cook until completely done.
In a large bowl, beat eggs with milk or cream. Add salt and pepper and cheese. Stir in greens and onion mixture. Pour into prepared dish. Bake until set in the center, maybe 45 to 55 minutes. Transfer to wire rack and cool 15 minutes, then invert onto a serving platter.