Heat 3 tablespoons of vegetable oil in a 3-quart saucepan. Saute a minced onion and 3 minced celery ribs until tender. Add 3 minced garlic cloves, a 141/2-ounce can of crushed tomatoes with juice and 1/2 cup tomato sauce. Stir and bring to a gentle boil. Add thin slices from a large lemon, stir and cook for about two minutes. Add 1 pound of shrimp, peeled and deveined, and salt, pepper and Tabasco to taste. Cook until shrimp turns pink. Sprinkle with minced green onions and parsley. Makes four servings.