As tomato season draws to a close, one (I) tends to finds oneself (myself) buying what is officially known as a “metric buttload” of tomatoes. Now, I can eat a lot of tomato sandwiches, but tomatoes have a window of ripeness rivaled only by avocados, so it helps to have a “use ‘em all up real quick” backup plan.

Enter my friend Amanda, who both grew and was gifted many metric buttloads of tomatoes this summer. Her solution to this “problem” of abundance was an elegant one: use the Instant Pot to pressure-peel the fruit, then—using the slow cook setting—concentrate the summery, umami-packed goodness by evaporating the excess water. You will need a food mill—I got one for 20 bucks—but the only ingredients you’ll need are tomatoes, some sort of liquid to bring the pot to pressure (I used wine), and maybe a big pinch of salt. It’s so simple, it barely counts as a recipe, but I’m happy to walk you through the process.

Photo: Claire Lower

First, grab any and all tomatoes you have (I had about five pounds), wash ‘em, and put them in the insert of your Instant Pot. Do not remove the stems (some say they add an herby note). Do not core them. Definitely don’t seed them. Add a cup of your favorite liquid. This can be water or wine, but stay away from anything with a higher proof, as liquor can create an ignitable vapor cloud, which is bad. 

Close the pot and press the “Manual” or “Pressure Cook” button. Using the “+” and “-” buttons, set the cook time to three minutes. Once that time has elapsed, let the pressure release naturally, then open the Instant Pot and transfer its contents to a big bowl.

Next, grab your food mill, and start squishing and milling the tomatoes back into the pot. At first you will be like “um, this is just tomato juice,” but do not fret. Keep going, milling those juicy bois until all you have left is stems, seeds, and skins. Don’t throw these out: Mix them with an equal mass of salt and dry them out in the oven to make tomato salt. (See the full process here.)

Leave the lid off the Instant Pot, press the “Slow Cook” button, and use the “Adjust” button to make sure it’s set to “Normal.” Let the sauce cook and condense for 15 hours, stirring every once in a while if you feel like it. I stirred maybe a total of three times during the cooking period, more for my benefit than the sauce’s.

This will give you about a liter and a half or very saucy sauce. I like to keep mine fairly loose, so I can cook it further with other ingredients and not worry about it getting too thick. If you want yours thicker, just cook it longer. If you want tomato paste, let it go for another 15 hours. Once you have reached your desired sauce consistency, spoon or decant it into jars or soup containers, and get it into the fridge or freezer. Repeat as needed until your tomato supply is depleted, making sure to take a tomato sandwich break every once in a while.

This article was written by Claire Lower on Skillet and shared by Claire Lower to Lifehacker from Lifehacker and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.