The Preparation
Cut bacon into half-inch pieces (freezing it slightly makes this easier).
Cook bacon in a pan over medium heat until it renders fat and gets some color, but do not make it overly crispy.
Remove bacon to a plate. Drain all but 1 tablespoon of bacon fat from the pan.
Add quartered and thickly sliced onions to the pan with the reserved bacon fat.
Season onions with salt and pepper.
Cook onions low and slow, stirring occasionally, until caramelized (10-15 minutes).
Add the dark brown sugar and stir to combine. The sugar will help with caramelization.
Add the garlic and cook for another minute.
Return the bacon to the pan.
Add coffee, balsamic vinegar, and water.
Turn heat to medium and let mixture reduce and thicken, stirring occasionally.
Continue cooking until the jam reaches a thick, jammy consistency (total cook time approximately 1 to 1.5 hours).
Adjust seasoning as needed.
