A roasted nut oil can give your vinaigrette a mild, earthy flavor—a nice change from bland vegetable oil or sometimes-overpowering olive oil.
What to buy: We like the La Tourangelle brand of roasted nut oils like this walnut oil. Avoid brands that use refined nut oils—they don’t taste like the nuts they came from. Store nut oils in the refrigerator or freezer to prevent rancidity.
Game plan: If you’re making the dressing ahead of time, add the minced chives just before serving.