Begin by picking over the lentils to remove any debris or broken pieces. Transfer the lentils to a fine mesh colander or sieve and rinse them thoroughly under cold water. Set aside while you prepare the other ingredients.
Peel and dice the onion. Remove the stems and seeds from the green bell pepper, red bell pepper, and jalapeño pepper (reserving an extra for serving, if desired), then dice them. Peel the garlic cloves and mince them finely. Also measure out all the remaining chili ingredients so you're ready to assemble everything easily.
Add the rinsed lentils from Step 1, diced vegetables and aromatics from Step 2, black beans, crushed tomatoes, vegetable broth, frozen corn, salsa, chili powder, ground cumin, dried oregano, smoked paprika, salt, and black pepper to a 6-quart slow cooker. Stir all the ingredients together to combine well. Secure the lid and set the slow cooker to HIGH for 5 hours or LOW for 9-10 hours, until the lentils are tender and the chili is thick and hearty. I like to use a spicy salsa for an extra kick, or you can add a pinch of cayenne if you enjoy more heat!
While the chili cooks, prepare a fresh pico de gallo. Dice the roma tomatoes, finely chop the white onion and jalapeño pepper (with seeds and stem removed), and roughly chop the fresh cilantro. Combine the tomatoes, onion, jalapeño, and cilantro in a bowl. Squeeze in the juice of half a lime and season generously with salt. Mix everything well. This fresh topping adds a bright, zesty finish over the hearty chili.
Once the chili is cooked and the lentils are tender, give it a good stir and adjust seasoning as needed. Serve the chili hot, topped with a generous spoonful of fresh pico de gallo from Step 4, a sprinkle of chopped fresh cilantro, crushed tortilla chips, shredded cheese, sour cream, sliced avocado, and extra jalapeño if desired. I always make sure to scoop plenty of pico de gallo and crunchy chips on mine for added flavor and texture. Enjoy your chili with rice, cornbread, or just as it is!