1. Rinse the lentils under cold water.
2. In a pot, combine lentils and vegetable broth. Bring to a boil, then reduce heat and simmer for about 20 minutes, or until lentils are tender.
3. In a skillet, heat olive oil over medium heat. Add diced onion and cook until translucent, about 5 minutes.
4. Add minced garlic, chili powder, cumin, paprika, salt, and black pepper to the skillet. Cook for another 2 minutes.
5. Add cooked lentils to the skillet and stir to combine. Cook for an additional 5 minutes, allowing the flavors to meld together.
6. Warm taco shells according to package instructions.
7. Fill taco shells with lentil mixture and top with shredded lettuce, diced tomatoes, shredded cheese, and sour cream.
8. Serve immediately and enjoy!