1. Stir together milk, carrot, green onion, bread crumbs, Italian seasoning, garlic salt, and pepper in a medium mixing bowl. Add ground turkey; mix well. Shape the mixture into four 1/2-inch-thick patties. Lightly grease the grill rack.
2. For a charcoal grill, place patties on the greased grill rack directly over medium-hot coals. Grill, uncovered, about 12 minutes or until an instant-read thermometer inserted into the side of a patty registers 165 degree F, turning once.
3. For a gas grill, preheat grill. Reduce heat to medium-hot. Place patties on grill rack; cover and grill patties as directed in step 2.
4. Meanwhile, stir together mustard and curry powder.
5. Serve patties on buns topped, if desired, with lettuce leaves, zucchini, sliced tomato, and curry mustard mixture. Makes 4 servings.