Drizzle olive oil in a large pot or Dutch oven over medium heat and cook diced onion and bell pepper for 4-5 minutes until softened; then add in garlic, sauté for an additional 1-2 minutes.
Add green lentils, taco seasoning, tomato paste and 4 cups of chicken broth to the pot; stir to combine and bring to a boil.
Reduce heat and simmer the mixture for 20 minutes, until the lentils are just about cooked through.
Stir in salsa, corn, and beans to the soup, and an additional cup of broth if the mixture looks too thick. Simmer for 15 minutes.
Season to taste with black pepper, and serve with your desired taco toppings and tortilla chips on the side.