Place the lentils and broth into a medium saucepan and place it over high heat. Bring the broth to a boil, lower heat, and allow to simmer until the lentils are tender, about 30 minutes.
While the lentils cook, heat olive oil in large pot over medium heat. Add the onion and red belle pepper, and sauté until softened, about 5 minutes. Add garlic and sauté another minute, until very fragrant. Add the crushed and diced tomatoes, porter, eggplant, sugar, cumin, and chili powder.
Bring the mixture to a low simmer and allow to cook over low heat until the eggplant is tender, about 20 minutes, stirring occasionally.
Drain any excess liquid from the lentils and stir them into the pot with the chili. Allow to simmer for 2 to 3 minutes longer. Season with salt and pepper to taste, then add some hot sauce if you'd like a bit more kick.