To make marinade, mix Worcestershire sauce, vinegar, brown sugar, garlic, oil, onion powder, black pepper, salt and liquid smoke in a bowl and blend until smooth.
Cut vegetables: dice potatoes; slice onions; slice bell peppers; trim green beans; slice carrots.
Dip carrots in marinade and lightly shake off excess, then set aside.
Dip potatoes in marinade.
Dip onions and remainder of vegetables in marinade.
Mix ground beef with remaining marinade and use your hands to gently blend marinade into meat. Be careful not to handle too much or meat will become tough.
Form ground beef into four equal sized (¼ pound) round patties. Place a dent in the center to help prevent shrinkage.
Cut 8 pieces of foil (18 x 12 inches). Spray interior side of 4 pieces of foil withPam spray.
Place two foil sheets together, sprayed side up and lay peppers, carrots and potatoes in middle of foil.
Lay ground beef patty on top of vegetables and lightly sprinkle meat with garlic salt.
For each packet, bring two of the sides together, keeping the food inside. Fold foil sides like a tent and turn down edges. Continue folding down top of triangle-shaped tent until it is snug against the food.
Fold end pieces together and up. Make sure edges are sealed. Continue with additional foil meal packets. Place foil packets on outdoor grill. (Flip over half way through.) Cook on high for 10 minutes. Turn down heat and cook on low-medium 20 more minutes. (You could also do this in the coals of a campfire, or in your home oven.)
Remove from grill and be careful as the foil will be hot! Cool to warm before serving. Serve on plate or in foil. Serve with barbecue sauce (optional).
Notes
To cook your foil dinner over a campfire: Start the campfire, then wait until you have some coals. When the fire turns to coals, make a flat surface and place tin foil dinners in the fire. Cook about 20 minutes and turn it over at least once while cooking so it cooks evenly.
Use cooking spray. Spray cooking spray on side of foil where you’ll place meat and vegetables. This will help prevent sticking.
Cut thin slices. Cut hard vegetables into thin slices for foil packets. Also, use thinner slices of meat or form medium-thin ground beef patties. This will allow them to cook more quickly.
Use heavy duty foil. Stronger foil prevents rips and leaks. It also protects your tin foil dinners from getting ashes in them. Use two layers of foil for your foil dinner on the grill; make sure to seal the foil packet well.