Heat a high-sided pan over medium heat. Add bacon and cook, stirring occasionally, until the bacon is rendered and slightly crispy on the edges, about 6-7 minutes. Remove bacon to a paper towel-lined plate and reserve. Add the red onion, chili, garlic, salt and pepper to the bacon drippings and cook for 5-6 minutes. Add apple cider, maple syrup, dark brown sugar and balsamic vinegar, and stir to combine.
Add reserved bacon back to the pan and cook for about 15 minutes or until the sauce has reduced a bit and the mixture looks sticky and thick. Remove from heat. Serve hot or cold. (If serving cold, allow the mixture to cool before transferring it to a storage container.)