Green Salad with Apples and Toasted Walnuts

Preheat the oven to 350 ° F. Place the walnut slices on a lined baking sheet. Bake the walnuts for 5-8 minutes, stirring every 2 minutes, until lightly browned. Pour into a bowl and let cool.Put the apples in a bowl and mix with 1 tbsp vinegar. In a small bowl, whisk together the remaining vinegar, mustard, shallots, and sugar; season with salt and pepper. While whisking constantly, drizzle with olive oil and continue whisking until smooth.Place the salad greens, apples, and walnuts in a large bowl. Drizzle with dressing before serving.