Stir in minced garlic and cook for 1-2 minutes until fragrant.
Add the rinsed lentils and vegetable broth to the skillet. Bring to a boil, then reduce heat to low and simmer for 20 minutes or until the lentils are tender and most of the liquid is absorbed.
Once the lentils are cooked, stir in tomato sauce, tomato paste, soy sauce, apple cider vinegar, maple syrup, smoked paprika, chili powder, and cumin. Mix well to combine.
Simmer for another 5-10 minutes to allow the flavors to meld together, stirring occasionally.
Taste and adjust seasoning as needed. Serve the lentil mixture on toasted burger buns.
Notes
For extra flavor, try topping with pickle slices or shredded vegan cheese. Use gluten-free buns if needed.