i’m the kind of guy who enjoys making things that accompany or augment other things – shrubs and bitters for drinks, infused vinegars for salad dressings, flavored olive oil for cooking and dipping, and this tomato-onion “jam” – perfect for eggs, fish, chicken, or as a filling in a grilled cheese sandwich!
this is super easy to make, and you can vary it easily according to your taste.
to make this particular recipe, i used about a tablespoon of olive oil, 2 medium yellow onions, and a 28 ounce can of peeled plum tomatoes.
all you have to do is chop the onion and saute it over medium heat until the onions are soft and starting to caramelize – about 10-15 minutes. while that’s going, take out the tomatoes from the can and chop them up. once the onion is ready, add the tomato and continue to cook. you can add extra tomato sauce from the can to help it blend with the onions, and be careful to watch the heat – tomatoes have a low specific heat and will boil easily; you want to avoid boiling.
the jam is ready after 20 minutes or so. you can cook longer or shorter – longer will give you a richer taste, while shorter cooking times will taste brighter but (to me) undercooked.
you can add garlic, basil, or oregano and you can easily change the balance of tomato and onion. you might even consider using red onion, and you can most definitely use fresh tomatoes, but i woud recommend skinning them first. keep it refrigerated, and use it within a week or so.