For best results, use fresh, seasonal vegetables. Feel free to substitute with your favorites, such as eggplant, corn, or halloumi cheese. If you don't have a grill, you can broil the kabobs in the oven. Place them on a baking sheet lined with parchment paper and broil for 5-7 minutes per side, or until tender and slightly charred. The lemon marinade can be prepared ahead of time and stored in the refrigerator for up to 24 hours. Brush the kabobs with the marinade just before grilling.