01 - If using wooden skewers, submerge them in water for at least 20 minutes to prevent burning on the grill.
02 - Set the grill to medium-high heat, targeting approximately 400°F. Allow the grates to fully heat before adding the skewers.
03 - In a small saucepan over low heat, melt the unsalted butter. 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. Set aside.
04 - Thread the zucchini rounds, bell pepper pieces, and red onion chunks alternately onto the skewers, distributing the vegetables evenly.
05 - Using a basting brush, generously coat the assembled skewers with half of the prepared garlic butter mixture.
06 - Place the skewers onto the preheated grill. Cook for 3 to 5 minutes per side, turning occasionally, until the vegetables are tender and lightly charred in spots.
07 - Remove the skewers from the grill and immediately brush with the remaining garlic butter while still hot.
08 - Arrange the skewers on a serving platter alongside fresh lemon wedges. Serve warm.