Whisk 2 teaspoons each whole-grain mustard and white wine vinegar, 1/4 teaspoon salt, and pepper to taste in a large bowl. Slowly drizzle in 3 tablespoons olive oil, whisking. Add 3 bunches torn arugula and1/3 cup chopped toasted walnuts and toss.
Photograph by Tina Rupp
Recipe courtesy Food Network Magazine