Step 1Mix the chicken, egg, matzo meal, parsley, tomato sauce, salt and pepper to taste. The mixture will be very moist. Shape it into 12 patties using wet hands. Coat each patty with some of the flour, then dip in the beaten egg mixture.
Step 2Heat 1/2 inch of oil in a large skillet over medium-high heat. Fry the patties in 2 batches until both sides are golden brown, about 2 minutes a side. Drain on paper towels.
Step 1Combine the broth, tomato sauce, water, salt, lemon juice, garlic, sugar and onion, if using, in a saucepan over medium-low heat. Cook until slightly thickened, 30 minutes.
Step 2Heat the oven to 350 degrees.
Step 3Spread half the sauce in the bottom of a 2 1/2-quart casserole. Arrange the fried patties in a single layer on top, then top with the remaining sauce. Bake for 40 minutes.