Lightly spoon flour into a dry measuring cup; level with a knife. Place flour in a 9-inch pie plate; bake at 350° for 45 minutes or until light brown. Cool on a wire rack.
Heat the oil in a large Dutch oven over medium-high heat. Stir in 3 tablespoons toasted flour, and reserve remaining flour for another use. Add chopped onion and celery, and sauté 2 minutes. Add the okra, chopped tomato, ham, and broth, and bring to a boil. Reduce heat, and simmer 45 minutes. Stir in minced garlic. Bring to a boil, and add the shrimp, crabmeat, and oysters. Cook for 2 minutes or until the shrimp are done and edges of oysters curl. Stir in the hot sauce.