A ridged griddle pan is ideal for cooking the tuna here, those bitter, burnt lines adding earthiness to the dish. However it isn’t essential; a frying pan will do.
Cook the potatoes in boiling salted water for approximately 20 minutes until cooked through. When they have cooled down, peel them. Cook the French beans in boiling salted water until tender, but still with a bite. Quickly drain, running them under cold water to stop the cooking.
Cut the beans, potatoes, spring onions, tomatoes, yellow pepper, anchovy fillets and ol