Heat oil in a deep, 10-inch skillet over medium-low heat. Add onion; cook until translucent. Crumble tempeh into the skillet; stir until golden brown. Add green pepper and garlic; cook until they begin to soften, 2 to 3 minutes.

Stir in tomato sauce, Worcestershire sauce, honey, molasses, coriander, thyme, oregano, paprika, cayenne pepper, celery seed, cumin, salt, and black pepper. Simmer another 10 to 15 minutes. Spoon hot onto hamburger buns to serve.