WHAT YOU'LL NEED
1 lb (I had about 450 grams) cherry/plum tomatoes
1 small (or 1/2 a large) yellow onion
1/2 cup roughly chopped sweet Thai basil leaves*
1/4 cup sugar
1 Tbs balsamic vinegar
1 Tbs lemon juice
1 Tsp kosher salt, or more to taste
up to 1/2 cup water, or as needed to create desired consistency
*Here in Thailand, Thai basil is just basil. Basil as we know it in America or Europe is much rarer to come by and it’s definitely more expensive. Here, and at asian stores, there are usually two types of Thai basil available, sweet and hot, and what I used here was the sweet. If your local grocery store doesn’t sell Thai basil, or regular basil is more affordable and attainable for you, by all means, you can of course use that here instead.
WHAT YOU'LL DO
First, wash thoroughly and then chop all the cherry tomatoes into quarters. Very small ones can be halved. Dice the onion. Put the tomatoes and onion in a medium shallow saucepan on medium-high heat and begin to cook, uncovered for about 5 minutes while you get all the other ingredients ready. The onions will start to sweat and the tomatoes soften and release their juices.
Add the rest of the ingredients besides the water, and cook, uncovered and stirring occasionally for about 20-30 minutes. The mixture should darken in color and thicken considerably. Measure out roughly 1/3 of the jam and pulse in a food processor or blender and add the puree back into the jam. (Alternately you could use a few pulses of an immersion blender). Continue cooking on medium heat, as it bubbles and thickens even more. After 10 minutes more minutes, taste and adjust seasoning as desired.
Note: My mixture got rather thick before I thought it was quite done cooking so after I had checked for taste, I poured in 1/2 cup water and continued cooking the mixture down for an additional 8-10 minutes. Most of the liquid burned off again, and I was at my desired consistency. But you may not feel that this is a necessary step for you at all.
Remove from heat and fill a sanitized (pint sized) jar or sterile glass container with your jam!
Put it on anything. Seriously though. Just about anything. Or eat it with a spoon. Not that I’ve done that or anything.
Enjoy for up to 3 weeks when stored in the refrigerator.