Preheat oven to 350 degrees Farenheit. Use a bit of the butter and soy flour to lightly grease and flour an 8-inch souffle dish. Heat remaining butter in a saute pan and saute zucchini slices, onion, and garlic until zucchini becomes translucent. Put sauteed mixture into food processor and pulse to mince. Pour into a large bowl and add the rest of the soy flour and all remaining ingredients except the eggs. In a separate bowl, beat egg yolks until frothy. Blend into the mixture. In a separate bowl, beat egg whites into soft peaks. Carefully fold into the zucchini mixture and pour mixture into prepared souffle dish. Bake for 30-40 minutes, until top is light to golden brown.