This simple mixture of aromatics is a building block — a wonderful base for countless recipes, including soups, beans, ragouts, stews, and sauces — and so versatile, I always have it on hand. Soffritto originated in Italy, but I first came across it in the basic preparations and technique section in Thomas Keller’s Bouchon cookbook.
Keller’s recipe consists of diced onion, extra virgin olive oil, kosher salt, grated tomatoes, and minced garlic. That’s it. I’ve seen many other renditions that add everything from diced red bell pepper to small amounts of tomato paste in lieu of the fresh grated tomato. But I always stick to the Bouchon ingredients. The resulting sauce is sweet, with just the right amount of salt to create a perfect balance.
The only downside to the Keller recipe is the time it takes to cook it on the stove top, all the while watching it carefully. All told, with preparation and cooking, the conventional version takes 5 to 6 hours and a diffuser to maintain an even, low heat. The sous vide version takes about 20 hours, but in this easy alternative cooking method you never have to “watch the pot.”
You first sous vide the onions, oil, and salt for about 15 hours until the onions are caramelized. Next you add the grated tomato purée, reseal the food bag, and cook an additional 5 hours. The raw minced garlic goes in at the end of the cooking process.
Soffritto freezes nicely in individual gastroflex molds or muffin trays. Once frozen, just pop them out into plastic bags and freeze for up to six months. You’ll have the foundation for all kinds of soups and sauces ready to go. Thaw before using, or use soffritto frozen for making recipes sous vide!
Makes 3 cups
- Preheat the water bath to 200°F (93°C).
- Divide the onions between two 1-gallon, zip-lock food bags. Add ½ cup of extra virgin olive oil and ½ tablespoon kosher salt to each bag. Seal the bags using the water displacement method. (The onions expel quite a bit of gas while caramelizing; you may want to double bag the onions or consider using bags with a valve or pump mechanism. Read more about it here.)
- Cook for 15 hours or until the onions are nicely caramelized.
- Meanwhile, slice the tomatoes in half lengthwise and remove and discard the seeds. Grate the tomatoes on the large holes of a box grater. The pulp will go through the grater, creating a nice purée, while the skin remains in your hand. Discard the skins. Refrigerate the tomato purée until it’s time to add it to the onions.
- After 15 hours, remove the onions from the water bath and very carefully open the bags. Add half of the tomato purée to each bag and reseal.
- Cook for an additional 4 hours.
- Remove the pouches from the water bath and carefully open the bags; the mixture will be very hot. Pour the bag contents into a bowl and add the minced garlic, stirring to combine. Allow the mixture to cool, then drain the oil. The oil is very flavorful and can be used for other cooking purposes. Transfer the soffritto to a lidded jar or storage container and refrigerate for up to 2 weeks. Or freeze for up to 6 months.