Walnut Vinaigrette

• 1 small shallot, finely diced
• ½ tablespoon red-wine vinegar
• ½ teaspoon Dijon mustard
• ¼ teaspoon salt
• 2 tablespoons walnut oil

Salad

• 100g mixed salad greens, such as frisée, watercress, escarole and/or curly endive, torn into bite-size pieces
• 1 small endive, cut crosswise into thin slices
• 1 small fennel bulb, trimmed and cut into 2-inch slivers
• 60g white mushrooms, sliced
• 20g chopped walnuts, toasted