Preheat oven to 350 degree F. Thaw crawfish or shrimp, if frozen. In a large skillet cook bacon over medium heat until crisp. Drain bacon on paper towels. Crumble bacon and set aside. Remove all but 1 tablespoon of bacon drippings from skillet. Reserve the remaining drippings.
Add the onion to the skillet. Cook and stir over medium heat until onion is tender. Carefully stir in the 1-1/2 cups water, tomato paste, sugar, and the 1/4 teaspoon salt. Cook and stir until heated through and tomato paste is dissolved. Remove from heat and set aside.
Spoon 3 tablespoons of the uncooked rice in each of four 6-ounce custard cups or four 8-ounce, individual souffle cups. Place cups in a shallow baking pan. Divide the tomato-onion mixture evenly among the custard cups (there should be 1/2 to 2/3 cup of tomato mixture per custard cup). Cover cups with foil and bake for 40 minutes or until rice is tender, stirring once.
If using uncooked shrimp, peel and devein. Rinse shrimp; pat dry. In a 3-quart saucepan bring 4 cups water and 1 teaspoon salt to boiling. Add shrimp. Cook and stir for 1 to 3 minutes or until shrimp turn pink. Drain; set aside.
Meanwhile, in a large skillet cook celery, sweet pepper, and garlic in 1 tablespoon of the reserved bacon drippings until vegetables are tender.
In a small bowl or cup stir the 1 cup cold water into cornstarch; add red pepper, black pepper, and the 1/8 teaspoon salt. Stir into skillet along with the cooked crawfish tails or cooked shrimp and cooked bacon. Cook and stir until thickened and bubbly; cook and stir for 2 minutes more or until heated through.
Remove rice from oven. Transfer to a wire rack. Let stand for 10 minutes. To unmold, loosen edges with a knife. Carefully invert rice mixture onto a shallow bowl or dinner plate; spoon a fourth of the crawfish mixture around mounded rice. Repeat with remaining rice and crawfish mixture. Makes 4 main-dish servings.