Method:
1 Heat oil in a frying pan over a medium heat, add the garlic, anchovies, capers and diced tomatoes, simmer for 5 minutes. Add the tuna steak, simmer for 4-5 minutes or until tuna is cooked to your liking. Season to taste.
2 Pierce the potatoes with a fork, microwave on High/100% for 3-5 minutes or until tender. Press potatoes through a ricer into a bowl (alternately peel and mash), add butter and cream and season with salt and stir until smooth.
3 Spoon the mash onto plate, top with the tuna and spoon over the sauce.