Position a rack in the middle of the oven and preheat to 375°F (190°C).
Spread 2 tablespoons of the oil on a half-sheet pan. Add the beef and lightly season with salt and black pepper. Roast for 5 minutes, or until the beef has very little pink remaining.
Add the onion, season with a pinch each of salt and pepper, and roast for about 10 minutes, or until the onion starts to brown. Add the bell peppers, garlic, chili powder, cumin, and oregano and stir to combine. Drizzle with the remaining 2 tablespoons oil and return to the oven. Roast for another 10 minutes, or until the peppers soften.
Add the tomatoes, beans, beer, coffee, brown sugar, cocoa powder, and salt to taste and stir to combine.
Carefully, using oven mitts, cover the sheet pan with foil and secure the edges by crimping around (you can also cover it with a turned-over sheet pan, if you like). Return to the oven and roast for about 40 minutes, or until the chili looks stewy and saucy and the vegetables are soft.
Remove the foil or top sheet pan and roast for another 10 to 15 minutes, or until the chili thickens. Remove from the oven, taste, and season with more salt and/or pepper, if desired.
Divide the chili among six bowls, top with the cilantro, avocado, scallions, cheese, and/or sour cream, and serve hot.