To Prepare Marinate:
In a large bowl whisk together oil, lemon juice, vinegar, garlic, oregano, and mint. Season with salt and pepper to taste.
ut vcheese into 3/4 inch cubes, zucchini into 1/2 inch rounds. Peeled red onions and cut into 3/4 inch chunks.
Add cheese, zucchini, onion, and tomatoes, and toss to combine.
Alternatively thread cheese, zucchini, onion, and tomatoes on skewers.
Light one chimney full of charcoal. When all charcoal is lit and covered with gray ash, pour out and spread the coals evenly over entire surface of coal grate. Set cooking grate in place, cover grill and allow to preheat for 5 minutes. Clean and oil the grilling grate.
Grill skewers over direct heat until cheese browns and zucchini has slightly softened about 5 minutes per side. Frequently brush them with the leftover marinate.
Remove skewers from the grill to a serving platter. Squeeze lemon wedges over skewers and serve immediately with warm pitta bread and Greek yogurt dip.