Heat olive oil in a large pot over medium heat. Add onion along with a large pinch of salt and pepper. Cook 4-5 minutes, stirring frequently.
Add garlic, chili powder, cumin, and sugar and cook for another minute, stirring frequently.
Stir in diced tomatoes, chipotles in adobo, black beans, lentils, and a large pinch of salt and pepper.
Then add tomato sauce and 2 cups vegetable broth.
Cover, turn heat to medium-high and bring to a simmer.
Reduce heat and simmer over medium-low for 5-7 minutes or until lentils are tender, stirring frequently. Add remaining cup of broth if desired.
Stir in the juice of 1 lime and season to taste with salt and pepper.
Garnish with Fritos, sour cream, and fresh chopped cilantro.
