Heat oil (or vegetable broth) in pot over medium heat.
Add onion and sauté 5 to 6 minutes, until soft and translucent. Add the green bell peppers, jalapeño peppers, and carrots and stir to combine.
Add the garlic, chili powder, cumin, smoked paprika, salt and pepper. Stir well and sauté a few minutes until fragrant.
Add the tomato paste, cooked lentils, diced tomatoes, pumpkin, and 1 cup vegetable broth. Stir well. Increase the heat to bring to a boil, then decrease the heat to medium-low, cover, and simmer 20 minutes until thick and bubbly.
Taste and adjust seasonings accordingly. If you like your chili on the sweeter side, add the maple syrup and stir to combine. Add the beans and stir. Cook another 1 to 2 minutes to heat through.
If you like your chili soupier, add an extra cup of vegetable broth and stir to combine.
Serve hot with your favorite chili toppings.