Ingredients
3 tablespoons Dijon mustard
3 tablespoons Champagne or white-wine vinegar
1/4 teaspoon sugar
1/4 cup lightly packed fresh mint leaves, finely chopped
1/4 cup minced red onion or shallot
1/4 cup extra-virgin olive oil
Kosher salt and freshly ground pepper
Preparation
In a bowl, whisk together mustard, vinegar, sugar, mint, and onion. (Or, if not using immediately, reserve mint and whisk in just before serving.)
Slowly whisk in oil; season with salt and pepper. Refrigerate in an airtight container until ready to serve, or up to 3 days.