Dice the onion. Mince the tempeh or crumble into small pieces. Slice up the zucchini then cut into small pieces. Mince the garlic.

Heat a large nonstick skillet over medium heat.

Add the vegetable oil, then the onion and cook for about 4 minutes, stirring frequently.

Add the tempeh pieces. Cook for another 3 minutes.

Then add the zucchini and garlic and cook for another minute.

Add the brown sugar to the nonstick skillet, mix well and cook for another minute. Add the remaining ingredients: chili powder, cayenne, Worcestershire sauce, soy sauce, tomato sauce, and tomato paste.

Cook for about 5 to 7 minutes until heated through and bubbling, stirring frequently.

Serve with hamburger buns.