In a 12-inch nonstick skillet set over medium heat, add the onions and beef. Cook, breaking the meat into small pieces, until the meat is cooked through and the onions are translucent, 7-8 minutes. Drain excess grease.
Stir in the tomato paste, Stubbs® Jalapeno & Honey Barbecue Sauce, ketchup, Worcestershire, and soy sauce and a pinch of black pepper. Bring the mixture to a simmer,and cook until the sauce is slightly thickened, 4 to 5 minutes. Add additional salt and pepper, to taste, if needed.
Top bottom buns with a few spoonfuls of the meat mixture and top with slices of muenster cheese. Slip under the broiler for 30 to 45 seconds or until melted.
Top with a spoonful more of the meat mixture, then add slices of jalapeño and crispy fried onions. Place the top bun and serve.