1 In a large bowl toss potatoes with olive oil, rosemary, salt and pepper; place on sheetpan and roast in 350°F convection oven 30-45 minutes or until golden brown. Remove from heat and cool.2 d mustard until smooth and pour over potato-apple mixture and toss to coat well.3 Cover and chill.4 Before serving, stir in walnuts and mix well. Adjust seasonings with salt and pepper.5 Serve as a composed salad or platter salad (optional: serve on a bed of baby spinach).