Basque tuna stew
Heat the olive oil in a saucepan over a low heat. Add the onion and cook for 8–10 minutes until soft and golden. Add the garlic and cook for a further 1 minute. Add the tomatoes, cover and simmer for about 30 minutes until thickened.
Meanwhile, mix together the potatoes and peppers in a large clean saucepan. Add 300ml/10fl oz water, which should just cover the vegetables. Bring to the boil over a medium heat, and simmer for 15 minutes until the vegetables are almost tender.
Add the tuna chunks and the tomato mixture to the potatoes and peppers, and season with salt and pepper. Cover and simmer for 6–8 minutes until the tuna is tender. Transfer to four warmed large individual bowls, and serve immediately.