Combine 1 large sweet onion, halved and thinkly sliced, 1 Tbsp. Chipotle Paste, 1 Tbsp beef broth, 1 Tbsp balsamic vinegar, 1 Tbsp veg oil, 1 Tbsp crushed fresh garlic and 1 Tbsp dark brown sugar in a 10-inch nonstick skillet with a lid. When coals are ready, placed covered pan on grill rack. Cook onion mixture for 15 to 20 minutes, stirring occasionally, until onions are carmelized and most of the liquid is evaporated. Remove pan from grill and set aside.