Preheat grill to approximately 350° F. Wash all vegetables.
Dice potatoes into 1/4-inch cubes. Slice carrots and squash into 1/8-inch pieces. Dice peppers, onions, mushrooms and green beans into 1/8-inch pieces. Cut broccoli into bite-size pieces. Combine all prepared vegetables in a bowl.
Cut corncobs into thirds (for a total of 12 pieces).
Combine beef and Worcestershire sauce in a bowl.
Divide ground beef into 12 patties (1/3 lb each).
Lay out 12 sheets of aluminum foil and lightly coat with cooking spray.
Place one beef patty and approximately 1/12th of vegetable mix on the foil. Top with 1 T Italian dressing and sprinkle with salt and pepper. Add one piece of eared corn to each foil set. Pull corners up around ingredients and fold/roll the foil to form a seal.
Place foil packets on the grill (all at once or in batches, depending on the size of your grill) and allow to cook until vegetables are tender and ground beef patty reaches an internal temperature of 160° F on a meat thermometer (approximately 10 to 12 minutes).
Remove from heat. Open packets and serve immediately.