Chef Yotam Ottolenghi's culinary journey takes him to Tunisia, where he dines on fresh fish, discovers the national obsession with fiery harissa paste and samples spicy merguez sausages. He begins with a visit to an open-air restaurant set in an idyllic cove and managed by a hermit, and serves grilled red mullet with a lemon and celery salad, before travelling to a seaside cafe, where he tries making brik - a fried pastry snack containing soft egg and tuna