Cook the bacon: Add the avocado oil and chopped bacon to a large skillet over medium-high heat. Cook until the bacon begins to render its fat. Remove the bacon from the skillet and set aside.
Soften the vegetables: Add the tomatoes and onions to the skillet. Cook until the tomatoes begin to burst and break down and the onions soften.
Simmer into a jam: Return the bacon to the skillet. Add the balsamic vinegar, reduce the heat to low, and simmer until the mixture thickens and becomes jam-like.
Season and finish: Season with salt and pepper to taste. Top with chopped chives, if using.
Serve: Spoon onto burgers, spread onto toast, or add to a charcuterie board and enjoy.
Notes
If you would like the Tomato Bacon Jam to be sweeter, add brown sugar or maple syrup to your taste. Start with 1 tablespoon and go up from there.