Preheat oven to 375ºF / 190ºC

Scrub the sweet potatoes well and pat them dry with a dish towel. Place on a baking tray and drizzle a very small amount of vegetable oil. Using your hands, rub the oil in a thin, even layer all over the potatoes. Prick each sweet potato with a fork a few times and put them into the oven to roast.

Depending on the size of your potatoes, they may take between 30 minutes to 1 hour for them to cook. Check at 30 minutes by squeezing a potato (using an oven mitt!). You can also insert a sharp knife or fork into the center. They should feel quite soft and the knife should easily glide all the way through. If not return to the oven and check again in 10 minutes. When done, cover tray with foil and set aside.

In a large, heavy pot or enameled cast-iron dutch oven, heat the oil. Add half of the ground meat and cook over high heat, breaking it up with a wooden spoon, until browned, about 5 minutes; transfer to a bowl with a slotted spoon. Brown the remaining ground meat and add it to the bowl with the first batch.

(For vegetarian, skip above step, add the oil to the pot and follow directions below)

Drain all but 2 tablespoons of oil and add the onions and jalapeños and cook over medium heat, stirring occasionally, until the onions are translucent, about 8 minutes. Add the garlic, tomato paste, chile powders, cumin and black pepper and cook for 5 minutes, stirring occasionally. Add back the meat (if using) and stir in the broth, beans, diced tomatoes, maple syrup, beer, and vinegar.

Bring up to a boil, lower the heat and simmer, covered, for one hour, stirring occasionally. Remove cover and simmer for 30 minutes longer, until chili is thick. Turn off the heat and stir in the chocolate until it’s fully melted. Add the lime juice, season with salt to taste.

Slice open a sweet potato, season with salt and pepper, and mash the flesh gently, forming a pocket. Add about 1/4 - 1/2 cup chili to the center and top with your favorite toppings.