Finely chop 2 of the chiles. The original recipe calls for the entire can, but I find that two chiles and the sauce is all the heat we can handle.
Heat a large Dutch oven over medium heat. Add chiles, onion, bell pepper, garlic, and sausage. Saute for 5 minutes or until tender.
Add chili powder and next 6 ingredients, through tomatoes. Stir to combine, then bring to boil.
Reduce heat and simmer for 30 minutes, stirring occasionally.
Remove from heat and add chocolate, salt, and pepper.
Serve with sour cream and baked tortilla chips.