Niçoise sandwiches with potato, anchovy and caperberry salad

1.Cook potatoes in boiling salted water until just tender, then drain and cool. Cut into 1cm-thick rounds. Cook beans in boiling salted water until just tender, drain and refresh in iced water, then drain again. Combine potatoes, beans, anchovies, onion, caperberries and olives in a large bowl. Place vinegar and olive oil in a separate bowl, and season to taste with sea salt and freshly ground black pepper.

2.For sandwiches, place tuna in a shallow glass or ceramic dish, drizzle with ¼ cup olive oil and rosemary, then cover and refrigerate for 15 minutes.

3.Remove tuna from marinade, season fish to taste, then barbecue or char-grill over high heat for 1-2 minutes on each side for medium, or until cooked to your liking. Brush bread lightly with remaining olive oil and barbecue or char-grill, cut-side down for 30-45 seconds. Lightly rub grilled bread halves with garlic clove.

4.Place tuna on each of 4 bread halves, top with tomato, egg and remaining bread halves, then serve immediately with potato, anchovy and caperberry salad to the side, drizzled with dressing.