NOTE: fire resistant gloves are highly recommended, it gets hot over the grill while stirring.
Start the coals in a chimney, if using coals, and while it’s heating up, prepare the ingredients.
Dice cold bacon and onion into small pieces. Smash and mince garlic cloves and measure the rest of ingredients so it’s easily accessible.
Once the coals are ready, add them to the grill and arrange a two-zone fire. (Spread coal evenly on one half of the grill and leave the other half without coals.) Place a cast iron skillet on the grill, on the coals side, close the grill and let it heat up for a few minutes.
When skillet is hot, add some oil and bacon pieces. Cook, stirring from time to time, until bacon is browned.
Move the skillet off direct fire and add garlic, onions, and brown sugar. Let onions cook and caramelize for 15-20 minutes. Stir it from time to time.
Place the skillet over direct fire again and add maple syrup, vinegar, and a pinch of cayenne pepper. (You can add a little more pepper if you’d like a more spicy bite the the jam.) Stir everything together and let it simmer for a few minutes.
Move the skillet back to cooler side and let it cook for about 15 more minutes, stirring occasionally.
Take the skillet off the grill and it’s ready to be blended.
Spoon out bacon and onion mixture into a food processor but leave about 3/4 of the grease liquid behind (not all of it.) Pulse the mixture in the blender a few times and your bacon jam is ready.
Store it in a jar with a lid, in the refrigerator.