Potato salad with pickled mushrooms and sweet shallots

Ingredients

• Pickling liquid
• 1/2 cup rice wine vinegar
• 1/2 cup sugar
• 1 cup water
• 1 tablespoon peppercorns
• 2 clove garlic, sliced
• 1 tablespoon peeled and sliced ginger
• Salad
• 300 gram mixed mushrooms of your choice (i used shiitake and oyster), sliced
• 800 gram new potatoes, cooked in boiling salted water until tender, then drained
• 2 knobs butter
• 2 medium shallots, thinly sliced (or use onion)
• 2 rashers streaky bacon, thinly sliced
• 1 teaspoon sugar
• 2 tablespoon chopped chives
• 1 cup watercress
• Dressing
• 2 tablespoon pickling liquid
• 2 tablespoon lemon juice
• 2 tablespoon extra-virgin olive oil