Marinate: In a large zip-top bag, combine garlic, lemon juice, asparagus, spring onions, peppers, zucchini, and halloumi. Season lightly with salt. Seal and refrigerate for at least 1 hour.
Prepare Grill: Preheat your grill to medium or heat your barbecue coals until they’re white-hot.
Assemble Skewers: Thread marinated ingredients onto 8 skewers. If using wooden skewers, soak them in water for 20 minutes to prevent burning.
Grill: Spray skewers with low-calorie cooking spray. Grill or barbecue for 8-10 minutes, turning occasionally, until cooked through.
Serve: Enjoy with a large mixed salad or steamed vegetables.
Tip: For a vegetarian option, replace the halloumi with firm tofu.