Rinse lentils and add to pot of water. Bring water to a boil, reduce heat and let simmer until most liquid is absorbed. (15-20 minutes) Drain any excess water and set aside.
While the lentils cook, heat olive oil in large skillet over medium heat. Add onions, pepper, mushrooms and garlic and saute until softened.
Add in cooked lentils, tomato sauce, maple syrup, worcestershire sauce and seasonings.
Let mixture simmer and cook for about 10 minutes - sauce should thicken.
Serve in toasted buns with toppings of choice