This caramelized onion and tomato jam recipe is easy to make and so versatile. The onions are cooked low and slow until they turn a nice deep brown color, becoming nice and sweet. Then balsamic vinegar is added to the pan, along with diced tomatoes and sugar. This is cooked down until the tomatoes break down a bit, turn a rich dark red color, and most of the liquid is evaporated. The result is a thick, glossy jam that tastes delicious on potatoes, grilled cheese, crackers, sandwiches, and on and on!
Some tomato notes:
- I left the skin on my tomatoes and they didn’t bother me a bit. The jam is chunky anyways so I thought the skins blended in with the texture just fine. But if you are an anti-skin person, feel free to skin your tomatoes first!
- Also, remember to de-seed your tomatoes first before adding them to the pot so the mixture isn’t overly wet. You are trying to cook the moisture out of the tomatoes anyways to create a thick texture, and you don’t want to work against that goal with watery, pulpy tomatoes. Just use your fingers to scoop each bit of pulp out of the crevices in the cut tomatoes. I thought it was kinda fun in a messy, squishy kind of way, but I like playing with my food so I may have taken more enjoyment in that than the average person.
- Feel free to use slightly less than stellar tomatoes here – you are cooking them down with caramelized onion and sugar, so they will get plenty sweet and the flavor will intensify. This is a perfect recipe for winter grocery store tomatoes.
Look at the tomato transformation here! From this…
This caramelized onion and tomato jam keeps well in the fridge for a week, so have fun adding it to all your favorite dishes! And if it’s home fries you’re after, check out my super fast recipe for 17-Minute Easy “Cheater” Home Fries!Print
This caramelized onion and tomato jam recipe is the perfect accompaniment for a cheese plate, potatoes, or sandwiches. The balsamic vinegar gives the jam a subtle tanginess that complements the sweet onion and tomato flavors.
- 1 tbsp. olive oil
- 1 large onion or 2 small onions, thinly sliced
- 1 tsp. salt, divided
- 2 lb. tomatoes, about 6 medium vine tomatoes
- 3 tbsp. sugar
- 3 tbsp. balsamic vinegar
- Heat olive oil on medium low in a large skillet
- Add thinly sliced onions to the pan and sprinkle with 1/2 tsp. salt
- Distribute onions in an even layer in the pan. Cook until onions are dark brown, about 30 minutes. Stir occasionally. If onions are getting too dark too quickly, turn heat down to low.
- While onions are cooking, prepare the tomatoes. Cut the stem out of each tomato and cut in half horizontally. Scoop out the seeds and pulp from each tomato and dice.
- When the onions are caramelized, add balsamic vinegar to the pan and stir. Then add the diced tomatoes, sugar, and remaining 1/2 tsp. salt.
- Cook until the tomatoes begin to break down, have thickened and lost most of their moisture, about 30 minutes.
- Serve immediately with your favorite dish or keep in a sealed container in the fridge for up to 1 week.