Pat the tofu dry with a towel. Wrap it with a dry towel and place a cast iron pan or cutting board on top to press out more of the liquid. Let stand for 15 minutes. Then cut the tofu into 1 1/2-inch x 1-inch pieces.
Preheat a gas or charcoal grill on medium high heat. (You can also use a stovetop grill pan. Just wait to heat it until you have the tofu and vegetables prepped).
In a large bowl, stir together the turmeric, cumin, paprika, cinnamon, ginger, coriander, 1 teaspoon salt, 1/2 teaspoon black pepper, juice of half a lemon and 3 tablespoons olive oil in a large bowl. Gently stir in the tofu, coating it in the mixture. Let it marinate for 15 minutes. Then thread the tofu onto skewers.
Toss the vegetables into the bowl with the remaining marinade. Thread them onto their own skewers.
Grill the skewers until the tofu and veggies are charred at the edges and have grill marks, about 2 minutes per side.
For the sauce, stir together the tahini, garlic, parsley, juice of half a lemon, pinch of salt and water in a small bowl.
Serve on a platter or on separate plates with couscous or pita bread. Drizzle with the sauce or serve it on the side.