Cook down the diced bacon over medium-high heat. Stir frequently to cook, about 15 mins or so.
Once the bacon has cooked through and is crispy with a slight chew, remove it but leave the drippings and about 1-2 tbsp of bacon fat in the pan. Add the onions and sauté for 3 minutes on medium-high heat.
Add the bourbon and burn off the alcohol, then let this cook down for 1-2 mins before adding the blueberries and let those cook down for 2-3 mins.
Then add the black coffee and stir it in before adding the lemon juice, brown sugar, salt and pepper. Then we can add the bacon back in and stir once more. Lower to medium-low heat to simmer for 40 mins. Stir in some fresh thyme at the end and set aside to cool slightly.