Lobster Salad with Lime Dressing

Ingredients

• 250 g small red new potatoes, washed
• 2 tablespoons low-fat mayonnaise
• 2 tablespoons Greek-style yogourt
• finely grated rind of 1⁄2 lime
• pepper to taste
• 1 cooked lobster, about 500 g
• 2 small shallots, thinly sliced
• 90 g snow peas, shredded
• 90 g seedless red grapes
• 90 g seedless green grapes
• 1 cup watercress
• 2 cups arugula to serve