½ cup chopped onion
2 pounds ground beef
¼ cup chili powder
1 teaspoon ground cinnamon
1 teaspoon ground cumin
¼ teaspoon ground allspice
¼ teaspoon ground cloves
1 bay leaf
½ (1 ounce) square unsweetened chocolate
2 (10.5 ounce) cans beef broth
1 (15 ounce) can tomato sauce
2 tablespoons cider vinegar
¼ teaspoon ground cayenne pepper
¼ cup shredded Cheddar cheese
Heat oil in a large saucepan over medium heat. Add onion and cook, stirring frequently, until tender, about 6 minutes. Add beef, in batches if necessary, and cook, breaking up with a wooden spoon, until browned. Add chili powder, cinnamon, cumin, allspice, cloves, bay leaf, chocolate, beef broth, tomato sauce, cider vinegar, and red pepper. Stir to mix well. Bring to a boil. Reduce heat to low; cover and simmer 1 1/2 hours, stirring occasionally. It is the best if you now refrigerate overnight. Remove the bay leaf. Reheat gently over medium heat. Serve over hot, drained spaghetti. Top with shredded cheddar cheese.