- 2 pounds ground sirloin
- 1 medium onion, peeled and cut in 1/2
- 2 tablespoons Worcestershire sauce, (eyeball it)
- 2 chipotles in adobo and 2 tablespoons of adobo sauce
- 2 tablespoons grill seasoning, (a couple of palmfuls), (such as Montreal Steak Seasoning by McCormick brand)
- 1 tablespoon extra virgin olive oil (EVOO), plus some for drizzling
- 3 cloves garlic, finely chopped
- 3 tablespoons brown sugar
- 1/4 cup vinegar
- 1 can crushed fire roasted tomatoes (15 ounces), about 2 cups
- Salt and pepper
- 12 slices, 1/2-inch thick, brick-cut smoked Cheddar or sharp Cheddar, (such Cabot brand), (optional)
- 12 small round rolls, split
- (Many markets sell mini Keiser rolls or use dinner rolls in any flavor you like)
Pre-heat grill pan to high.
Place the meat in a bowl. Cut the onion in half. Grate half the onion into the meat using the small grate on a box grater. Chop and reserve the other half onion. Add Worcestershire, chipotles and sauce and grill seasoning to burgers. Drizzle a little EVOO over the bowl and mix meat. Score the meat into 4 sections. Make 3 mini-burgers, each 3 inches wide, 1-inch thick, from each half-pound of meat.
Heat a small sauce pot over medium heat. Add EVOO and garlic. Cook garlic 2-3 minutes then add sugar and vinegar, cook 2 minutes more and stir in tomatoes. Season sauce with salt and pepper and allow it to reduce 5-6 minutes more.
Grill meat 2-3 minutes on each side and top with cheese, if you like.
Place burgers on buns and top with raw chopped onions and warm fire roasted ketchup and serve.