large red bell pepper, deseeded and cut into 1 1/2 inch-squares
large zucchini, cut into 1 1/2-inch pieces
large white or yellow onion, cut into 1 1/2-inch pieces
white mushrooms, washed and trimmed
For the barbecue sauce:
15-ounce can tomato sauce
tamari or soy sauce
apple cider vinegar
red pepper flakes
Whisk all barbecue sauce ingredients together. Pour the sauce into a casserole dish (9 x 13 is fine, as is 9 x 9) and add the vegetables and tempeh. Coat the vegetables and tempeh well, and allow them to marinate in the fridge for two hours (or overnight).
Divide the vegetables and tempeh evenly onto the skewers, alternating ingredients. Reserve some extra sauce for serving.
Heat the grill to medium-high. Place skewers on the grill and cook, basting occasionally, for 7 to 10 minutes, or until the vegetables are tender and everything is browning. You can also do this on a grill pan, and cook for 8 to 10 minutes on medium-high heat. Serve immediately.