Preheat the oven to 350 degrees F (175 degrees C).
Saute the onions, garlic and zucchini in a little olive oil til onions are tender. Pour off any liquid that may be in bottom of pan. Season with salt and pepper to taste. Set aside til cool.
Sift flour and baking powder together into a large bowl. Lightly beat eggs, and mix them into the flour with the oil. Add the cheddar cheese. When the sauteed veggies have cooled, add them to the flour mixture also.
Pour mixture into a well-greased 9x13 inch baking dish, and sprinkle with paprika and parsley.
Bake in preheated oven for one hour.
Let the souffle set for about 15 minutes before cutting.