01 - If using wooden skewers, submerge them in water for at least 20 minutes to prevent burning during grilling.
02 - Set the grill to medium-high heat, targeting approximately 400°F, and allow it to fully preheat.
03 - Melt the butter in a small saucepan over low heat. Add the minced garlic and cook for 1 minute until fragrant. Remove from heat and stir in the chopped parsley, lemon zest, salt, and black pepper.
04 - Thread the zucchini rounds, bell pepper pieces, and red onion chunks onto the skewers in an alternating pattern.
05 - Generously brush the assembled skewers with half of the prepared garlic butter mixture, coating all sides evenly.
06 - Place the skewers on the preheated grill. Cook for 3 to 5 minutes per side, turning occasionally, until the vegetables are tender with light char marks.
07 - Remove the skewers from the grill and immediately brush with the remaining garlic butter. Arrange on a serving platter alongside lemon wedges and serve warm.