For something light and bright, look to a warm green vinaigrette. It gets its color from lightly fried capers and juicy Castelvetrano olives in oregano-infused oil before a trio of acids get whisked in: Dijon mustard, biting preserved lemons, and white wine vinegar. Tart and savory, it feels right at home poured over delicate, flaky white fish, like a trout baked en papillote or silky steamed sea bass. It will also hold its own atop a meatier slow-roasted pork shoulder. And if there is leftover sauce, it’s great spooned over creamy mounds of ricotta.
- In a small skillet over medium-low heat, add the 3 tablespoons of olive oil and sprigs of oregano. As the oil heats up, it may sputter a bit with the oregano. Once the sputtering picks up and the oregano leaves have gone a glassy green and stiff (about 3 minutes), remove the sprigs with small tongs or a fork, and transfer them to a paper-towel-lined plate.
- Add the chopped capers to the oil for 1-2 minutes until lightly browned, then add the olives, cooking an additional 1 minute, stirring regularly just to lightly fry. Turn the heat off.
- Add the Dijon mustard, preserved lemon, and white wine vinegar, and whisk (mixture may sputter). Then add the remaining ½ cup olive oil and pulverize the fried oregano leaves between your fingers before adding to the vinaigrette. Stir well to combine. Season with the salt and a few cracks of freshly ground black pepper. Use warm or at room temperature. Store refrigerated, and temper in a skillet or saucepan over low heat when ready to use.