Sauté the Veggies – Heat olive oil in a large skillet over medium heat. Add the diced onion and cook for 3-4 minutes until softened. Stir in the garlic and cook for another 30 seconds.
Build the Flavor – Stir in tomato paste, smoked paprika, chili powder, cumin, onion powder, salt, and black pepper. Let it cook for 1 minute to deepen the flavors.
Simmer the Sauce – Pour in the tomato sauce, vegetable broth, soy sauce, maple syrup, and apple cider vinegar. Stir and let it simmer for 3-5 minutes.
Add the Lentils – Stir in the cooked lentils until well coated. Reduce heat to low and let simmer for another 5 minutes, stirring occasionally. If the mixture is too thick, add a splash of broth.
Assemble & Serve – Toast the buns if desired, then scoop the sloppy joe mixture onto each bun. Top with pickles or coleslaw for extra crunch and enjoy!