In a large saucepan, heat the oil over medium heat. Add the onion, garlic, and a pinch of salt, stir, and cook for 4 to 5 minutes, until the onion starts to soften.
Stir in the fresh jalapeño and 1 cup (250 mL) of the bell pepper and cook for a few minutes more. Add the chili powder, cumin, oregano, and paprika and stir to combine.
Pour in the diced tomatoes with their juices and stir. Increase the heat to medium-high and bring to a simmer.
Stir in the tomato paste, lentils, and kidney beans. With a potato masher, roughly mash one-third of the mixture—don’t try to mash it smooth, just until it’s slightly thickened.
Add the vinegar, salt, black pepper, and sriracha. Cook over medium heat for 5 to 10 minutes, or longer if desired, until thickened to your liking.
Into individual bowls (or a 2 1/2- to 3-quart/2.5 to 3 L cast-iron pot or glass dish), ladle a layer of chili. Top with a layer of the cheese sauce. Keep layering until the chili is used up and you’ve added as muchcheesesauce as you prefer (I usually reserve 1/2 cup/125 mL of the sauce for another use). Top the dip with the remaining bell pepper, pickled jalapeño, and a sprinkle of sea salt.
Serve immediately with corn tortilla chips. Let any leftovers cool completely (otherwise, the steam will create more water in the dip) before transferring to a container and refrigerating for up to 5 days. Reheat leftovers in a saucepan on the stovetop while stirring to combine with the cheese sauce. Cooled leftovers can be frozen in freezer-safe zip-top bags with the air pressed out or in freezer-safe containers filled to the top (to prevent freezer burn) for up to 1 month.