Begin by selecting and washing your tomatoes. If blanching, boil water in a large pot.

Make a small "x" on the opposite side from the stem and place tomatoes into boiling water for 2 minutes, until the skin starts to peel back slightly.

Immediately scoop up tomatoes and transfer them to an ice bath.

Peel tomatoes (the skin should peel back very easily!), and quarter.

Add oil to the bottom of the Instant Pot and place cut tomatoes on top of it. If the tomatoes aren't super juicy, add ¼-1/2 cups of water. I generally like to add at least ¼ a cup to be safe). Adding liquid is necessary for the Instant Pot to pressurize.

Add remaining ingredients and secure lid. Make sure the vent is in the sealing position.

Set to High Pressure for 20 minutes. Allow to natural release for 10 minutes and then quick release the rest of the way.

There may be a good deal of liquid, you can do one of two things. Ladle some out or turn the Instant Pot to the "saute" function and allow the water to evaporate. This can take some time, but you are only concentrating the flavor of the sauce which is a win in my book!

One the sauce is less watery, use an immersion blender to blend sauce to desired thickness. Allow to cool and store in the fridge for days or the freezer for months.