In a medium bowl combine carrot, green onions, bread crumbs, milk, garlic salt, Italian seasoning, and pepper. Add ground meat; mix well. Shape mixture into four 1/2-inch-thick patties.
Place patties in a single layer in a freezer container; seal and freeze for up to 3 months.
To serve, thaw in the refrigerator overnight. For a charcoal or gas grill place patties on the grill rack directly over medium heat. Cover and grill for 11 to 14 minutes or until done (160 degrees F for beef; 165 degrees F for poultry), turning once halfway through grilling.
Meanwhile, for curry mustard, in a small bowl combine mustard and curry powder.
Spread bottoms of buns with curry mustard. Fill buns with burgers, lettuce, tomato, and zucchini.