Prepare couscous according to package directions. Meanwhile, in a small bowl or cup, combine garlic, chili powder and Worcestershire sauce; set aside.
Heat the olive oil in a large skillet with a tight-fitting lid over medium heat; add onion, bell pepper and carrot and sauté until onion is translucent. Add garlic mixture; cook and stir for 3 minutes.
Add tomatoes, tomato sauce, beans, basil, cumin and cayenne pepper. Reduce skillet heat, cover and simmer for 30 minutes. Salt to taste then serve chili over hot couscous.
Garnish with minced onion, shredded Cheddar cheese and diced avocado, as desired.