Like almost all dishes involving wine, use what you yourself drink. You can go seasonal with the wine–lighter reds or ros├ęs in the summer, rich cabs in the winter…

1/3 c scallions, sliced (1 large)
1/4 c red wine
3 T red wine vinegar
1 – 2 garlic cloves, coarsely chopped
salt and pepper, to taste
1/2 – 3/4 c mayo or replace part of the mayo (1/4 c) with heavy cream

1. Combine all ingredients except mayo (or mayo/cream) in a blender. Whizz until the scallions and garlic are finely chopped. Add mayo and blend until smooth. Transfer to a jar or small bowl. Refrigerate (if you have time) until cold. Shake or whisk dressing before serving.