1/4 cup fresh/frozen raspberries (optional)
1/4 cup raspberry vinegar (or white wine vinegar)
1 small shallot, chopped very fine (about 2 Tbsp)
1/2 cup olive oil
Sea salt and & freshly ground pepper, to taste
Combine vinegar and shallot in a bowl. In a slow, steady stream, pour in olive oil while whisking.
For more intense raspberry flavor, or if you do not have raspberry vinegar, combine fresh or frozen raspberries with the other ingredients and mix in a blender until smooth.