Saute onions in butter over medium high heat in large saucepan until translucent, about 3 minutes. Add tomato paste, chili powder, cocoa powder, and cumin, and cook until mixture carmelizes to a dark brown, about 10 minutes. Stir in carrots, celery and jalapenos and stir to coat. Add crushed tomatoes and beans. Stir in beer to our preferred consistency. Simmer for at least an hour, up to 2 hours.
Preheat broiler. Stir Mozzarella and Monterey Jack cheese into chili and top with shredded Cheddar. Broil until cheese is bubbly, about 4 minutes. If transporting, cover and wrap in thick towels. Grill to reheat if necessary.
Makes about 8 cups. For an extra-large batch, simply double the recipe.