Cube the lamb into small pieces and add it to a large bowl. In a separate bowl, mix together the avocado oil, olive oil, grated garlic, fresh oregano, Blackstone Tuscan Herb seasoning, and red wine vinegar to create the marinade. Pour the marinade over the lamb, ensuring all pieces are coated. Cover and refrigerate for at least 4 hours or up to overnight.
Thread the marinated lamb onto metal skewers. Preheat the Blackstone griddle to medium heat or use a pizza oven. Place the skewers over the cast iron skillet or on a foil-lined tray. Cook the lamb, turning the skewers as needed, until the meat is charred and cooked through. Cooking time will vary based on the size of the lamb cubes and your desired doneness. Once cooked, remove from the heat.
While the lamb is cooking, toss the sliced zucchini, chopped onion, and grape tomatoes in a bowl with olive oil and Blackstone Tuscan Herb seasoning to taste. Griddle the veggies on medium-high heat for about 3-5 minutes, stirring occasionally. At the same time, toast the naan bread on the griddle, flipping to toast both sides.
Serve the lamb skewers, griddled veggies, and naan bread family-style on a large board. Add garlic dip and tzatziki sauce for dipping. Enjoy!