Ingredients

　　2 tablespoons olive oil

　　1 tablespoon sesame seeds

　　1 scallion

　　2 teaspoons balsamic vinegar

　　1/2 teaspoon Dijon mustard

　　1/2 head radicchio

　　1 bunch arugula

　　In a small skillet heat 1 tablespoon oil over moderate heat until hot but not smoking and cook sesame seeds, stirring, until pale golden, about 1 minute. Mince scallion and in a small bowl whisk together with sesame seeds, remaining tablespoon oil, vinegar, mustard, and salt and pepper to taste until emulsified. Tear radicchio into bite-size pieces and in a bowl toss together with arugula and vinaigrette.