In a large skillet cook onion and sweet pepper in hot oil for 5 to 7 minutes or until tender. Stir in ground-meat substitute, tomato puree, the water, barbecue sauce, mustard, soy sauce (if desired), chili powder, and garlic.
Bring to boiling; reduce heat. Simmer, uncovered, for 20 minutes, stirring occasionally. Serve on buns. Makes 8 to 10 servings.