Combine 1/4 cup chopped celery, 1/4 cup chopped onion, 2-1/2 cups cooked tomatoes, 1/2 tsp. salt sprinkling of pepper, 2 tsp. Worcestershire sauce. Cover; simmer 10 minutes. Press through sieve. Heat 2 tbsp. fat or salad oil; blend in 2 tbsp. flour. Slowly add tomato mixture. Cook, stirring till thick. Add 4 cups cooked shrimp. Place spaghetti on platter and top with shrimp mixture.