Drain spinach and squeeze excess water out. Mix all ingredients. Divide evenly into patties and fry in nonstick skillet. 4 servings of 3 cakes each.
Mushroom Sauce Option: Brown one small can of mushrooms in the same skillet you fried the burgers in. Add more onions if you like. Add 2 cups of water to the skillet and bring to a boil. Add all the seasonings. Stir up 2 Tbs. cornstarch into about a 1/4 C. water. Add this mixture to the skillet stirring constantly until it starts to thicken. Add the burgers to the gravy and serve over rice, noodles, or mashed potatoes.