"I love potato salad - it's something that comforts and nourishes me," says Marty Boetz. If you have time, marinate the potatoes a day ahead.
500 gmkipfler potatoes, scrubbed50 mlwhite wine vinegar1egg, at room temperature1 cup (loosely packed)watercress sprigs½ cup (loosely packed)flat-leaf parsley, torn100 mlolive oil1smoked rainbow trout, coarsely flaked (skin and bones discarded) 3dill pickles, quartered or slicedTo serve:salmon roeTo serve:whole-egg mayonnaise
Place potatoes in a large saucepan, cover generously with cold salted water, bring to the boil over medium-high heat, reduce heat to medium and gently boil until tender but holding their shape (30-35 minutes). Drain, then, when cool enough to handle, peel and slice into thick rounds. Combine in a bowl with vinegar, season to taste and stir to coat. Refrigerate for flavours to develop (at least an hour, or overnight).
Cook egg in a saucepan of boiling water (8 minutes for hard-boiled), drain, refresh under cold running water, peel and set aside.
Add watercress, parsley and oil to potatoes and mix well with your hands until leaves are coated and glossy. Layer the potato mixture, trout and dill pickles on a platter. Top with salmon roe, finely grate egg over, dollop with mayonnaise to taste and serve.