In a hot skillet sauté onion and sweet pepper for about two minutes. Add cumin, chili powder and sugar then stir. Add diced franks and cook until slightly crispy. Stir in diced tomatoes and mix well. Set chili aside to cool.
In a medium bowl, combine chili and cheddar cheese and pepper jack cheese.
Transfer to a small baking dish. Top with remaining 1/4 cup of cheddar jack cheese and bake for 30 minutes or until cheese is melted and dip is heated through.
Garnish with sour cream, tomatoes and cilantro and serve immediately with French bread.