Clean bell peppers and place in stove with an inch of water in large pot. Let boil on medium for 8-10 minutes (until they're still firm enough to stand in bowl). In separate medium sized pot combine tomato sauce, mustard, sugar and onion with 1-1/2 cups water. Let boil on high for 1 hour. Add shrimp, crab meat and eggplant. Cook on low for 1 hour. Slowly add bread crumbs and stir at same time. (Use all but about one-quarter of bread crumbs). Remove from heat. Drain bell peppers and place them back in original pot. Fill bell peppers with ingredients cooked in other pot. Use the remaining bread crumbs on top of the stuffed bell peppers. Add 1 inch water in pot and boil on high 4 minutes.
Cajun Country -- New Iberia, Louisiana