New York-style sweet ’n’ sour onions
4 large white onions, sliced thin
1 teaspoon vegetable, grape-seed or canola oil (canola is best)
½ teaspoon salt
1 can of San Marzano tomatoes, whole, peeled (12 oz.)
¼ cup plus 3 tablespoons red wine vinegar
¼ cup granulated white sugar
1 tablespoon salt; add more to taste
1. Heat a large, wide pan over medium heat and add the oil. Once the oil is hot, add the onions and the salt and stir immediately. Cook the onions over medium heat until completely softened, but do not let them color at all.
2. While the onions are cooking, puree the tomato, vinegar, sugar and tablespoon of salt in the blender until completely smooth.
3. Once the onions are completely softened, add the tomato mixture and cook down until completely dry, about 25 minutes over low heat. Let this mixture cool overnight before using.