Place all yogurt sauce ingredients in a small mixing bowl and stir until combined. Refrigerate until ready to serve.Preheat your grill to roughly 400F.In a very large mixing bowl, place cauliflower, potatoes, onion, tomatoes, peas, and tofu or chickpeas. Drizzle coconut oil over the top of the veggies and stir until coated. Add curry powder and a pinch of salt & pepper, stir again until evenly coated.Then, lay out four large rectangles of aluminum foil (approximately 12"x16"), divide curry cauliflower mixture between the four sheets and pile it in the center of each one.Take the longer sides in to meet each other, then fold over a couple of time to keep it in place. Fold remaining ends in the same manner (as pictured) to create an envelope/packet.Place each packet on the grill and cook for 7 minutes with grill cover closed. Flip and grill for an additional 7 minutes. Carefully open one packet slightly and poke the cauliflower/potatoes to see if they are tender, if not cook until they are (shouldn't take long at all).Once cooked through, place packets on a cooling rack for five minutes before serving/opening. When the packets are opened, squeeze ½ tablespoon lemon juice over each one, along with salt and pepper, to taste. Serve packets alongside yogurt sauce and enjoy!