2 tablespoons butter
1/3 cup minced onion
2 minced cloves garlic
2 teaspoons chili powder
1/2 teaspoon cumin
1/2 teaspoon black pepper
1/4 teaspoon oregano
1/4 teaspoon salt
30 ounces tomato sauce
1 ounce unsweetened chocolate
2 tablespoons brown sugar

In large skillet, melt butter over medium heat. Add onions and garlic and cook till tender. Stir in spices. Cook 2 minutes, stirring frequently. Stir in tomato sauce and cook 10 minutes, stirring frequently. Add chocolate and brown sugar, stirring till melted and smooth.