Caramelized Red Onion and Tomato Jam on Crostini

Heat olive oil in a small pot over medium-low heat. Add onions, salt, pepper, and 1 tablespoon balsamic vinegar. Stir to combine, then let the onions caramelize, stirring only occasionally, about 10 minutes. Once the onions are caramelized, add the garlic and thyme and let the garlic soften.

Stir in the tomato paste, and then add the chopped tomatoes and red pepper flakes, and the remaining tablespoon of balsamic vinegar. Season to taste with salt and pepper.

As the tomatoes cook, their juices will come out and the mixture will start to simmer. Turn down the heat, cover, and let simmer for 45 minutes to an hour, stirring occasionally.

Spread on toasted baguette slices and sprinkle parmesan cheese on top.