Fill the All-Clad TK 5 Qt. Sauce Pot with water and bring to a rapid boil. While the water is heating, use a paring knife to cut out the stem from each of the tomatoes and score an “X” through the skin on the opposite end. Fill a large bowl full of ice water. Plunge the tomatoes in the boiling water for about 5 seconds or until the skin begins to slip off the tomatoes. Use a slotted spoon or skimmer to transfer the tomatoes to the bowl of ice water.
When the tomatoes have chilled remove them from the water. Discard the boiling water and ice bath.
Cut the tomatoes in half. Place a strainer over the mixing bowl and squeeze all of the seeds out of the tomatoes and into the strainer. Press all of the liquid from the seeds then discard the pulp. Chop the peeled and seeded tomatoes very finely and combine with the juice then set aside.
Wipe the All-Clad TK 5 Qt. Sauce Pot dry, then place the pan over medium/low heat. Add the olive oil followed by the onions and a teaspoon of salt. Cook the onions slowly, stirring occasionally until they reduce in volume and become golden brown in color.
Add the garlic and cook for a few more minutes. Add the tomatoes and their juice, bay leaf, and 1 teaspoon salt. Cook the tomatoes down until all of the excess liquid has been reduced and the tomatoes just begin to fry in the oil. Adjust the seasoning with salt. Discard the bay leaf.
The soffrito can be used as a base for sauces, stews, soups, pastas, and grains. Store the soffrito refrigerated for up to a week. To use the soffrito, pour off the olive oil covering the surface and reuse it for another batch of soffrito. Spoon out the desired quantity of soffrito, then cover with the oil again.