Soffritto (mirepoix, holy trinity.etc) is the base flavor for a dizzying array of dishes. Although the quantities and ingredients vary a bit, we're generally talking onions, celery and carrots plus maybe garlic, sauteed in a fat.
Most of the time I love the act of soffritto - it's the prelude to so much good stuff, and assembling, peeling, chopping and sauteeing is a ritual. But, sometimes, not so much. It occurred to me that it doesn't really matter if I'm making one ounce or a pond of soffritto, it's about the same amount of effort (particularly if I deploy the food processor). I've been exploring freezing food in different stages of preparation for some time and have had good luck with the "log" approach, where I form the ingredient into a log shape and freeze it. This allows me to saw off a hunk and return the remains to the freezer, no muss, no fuss. With the following recipe and approach, you can simplify the preparation of soups, sauces like gravy and ragu, pot roasts and pretty much anything that calls for some aromatics sauteed with vegetables. —Mark A. Denner
My preferred ratio is 1:1:2 for carrot/celery/onion, but let's not be dogmatic. It's probably easiest to do this by weight, but you can just eyeball it as well. Chop roughly by hand or cut into 2-3" pieces and toss into your food processor. Opinions vary regarding how finely you should chop these ingredients.
Heat the butter or oil in the pan over medium heat and throw in all the other ingredients. Saute until you're happy - maybe a long time, maybe quickly. Some like it slightly brown, some insist it must never be browned. Opinions vary.
When complete, allow it to cool so it will no longer burn you. I like to use freezer paper, but wax paper works as well. Dump the soffritto into the middle of the paper, roughly form it into a log shape and roll the ends like a Tootsie Roll. Generally you don't want the diameter of the log to be more than 2" or so, but you decide. Put it into a gallon zipper top bag, or live dangerously and just put the log directly into the fridge. Alternatively, dump the soffritto into a gallon bag, form it into a log and toss this into the freezer.
To use, remove from the freezer and use a serrated knife to saw off a hunk (the fat should be relatively soft even at freezer temp so this is easy). Be careful of your fingers, please. I generally use a one cup = 2" hunk rule, but I could be wrong. Toss the hunk of soffitto into whatever called for something resembling soffritto. Smile and have another drink of wine.