Seared Yellowfin Tuna with Parmentier Potatoes

This is the most succulent steak ever which I cooked at home last night.  I bought the Yellowfin Tuna (Thunnus albacares) steaks fresh from The Good Fish Shop in Haslemere. It is sushi grade tuna which is the best cut from the loin and has very little sinew (white stringy threads).  Their tuna is caught from small boats using a pole fishing technique which is sustainable and very fresh.  Always check the freshness when you buy tuna like this.  As it ages it produces histamine which gives the fish an unpleasant smell and tastes metallic.  This is undesirable and can be hazardous to people with an allergy.  


To cook the tuna I marinaded it for 1/2 hour in lime juice and olive oil with a bit of freshly ground black pepper and then seared the surface in a hot frying pan for just 1 minute each side. The steak should still be red in the middle.  The 'parmentier' potatoes are cubed with garlic butter and rosemary and were bought ready made from Waitrose. I added a side salad of rocket, watercress and tomato.