In a large pot, warm the olive oil over medium heat. Add the onion then cook for a few minutes, until translucent.
To the pot, add the carrot and celery. Cook for about 5-7 minutes. Add the minced garlic, chili powder, smoked paprika and mustard powder. Stir together and continue to cook for another 5 minutes.
Next, add the crushed tomatoes, ketchup, apple cider vinegar, vegan Worcestershire, maple syrup and vegetable broth. Bring to a low boil then reduce to a simmer and cook for about 10 minutes, until sauce has thickened.
Lastly, add the cooked lentils and stir until evenly combined. Add salt and pepper, to taste.
Serve warm over toasted buns with pickles (optional), and enjoy!