In a large mixing bowl, whisk together soy sauce/tamari, chilli powder, brown sugar, garlic powder, chili powder, black pepper, and oil.
Add tempeh and veggies to the bowl and toss to coat. Let it marinate for 20 minutes.
Preheat grill/broiler on high and assemble skewers by mixing veggies and tempeh bamboo skewers.
Grill for 5 minutes on both sides or until browned and veggies slightly tender. Brush with the remaining marinade mixture over the skewers as they cook.