Heat a large cast iron skillet over medium high heat and cut the bacon into ½" pieces. Cook until chewy, then remove with a slotted spoon and set aside. Remove all but 1 T of the fat from the pan and add the onions, cooking until soft (about 10 minutes). Add the sugar, turn the heat down to low, and cook until caramelized-- about 20 minutes. Add the coffee, water, and reserved bacon and cook on medium low until the mixture cooks down and starts to get nice and jammy, which should take anywhere from 15-30 minutes. When it's thick and delicious looking, turn off the heat and stir in the balsamic vinegar. Serve warm, or store in a sealed jar in the refrigerator for no more than 1-2 weeks (not that you will have any problem finishing it immediately).
Recipe by Food Final Frontier at http://foodfinalfrontier.com/caramelized-bacon-chutney/