Preheat the oven to 385° and line a baking pan with parchment paper. Put the carrots and onion in the baking pan and drizzle the olive oil over them. Toss well to coat and then spread them evenly in the pan. Sprinkle ground sea salt and ground pepper evenly over the top.
Cover the pan with aluminum foil and roast for twenty minutes, remove the foil and roast for ten more minutes. The carrots and onions should be nice and soft, and lightly caramelized. Add BBQ sauce and mix evenly.
Use whatever you want, in a burger, as a side, etc.