Sesame Tuna with Lime Mash

Ingredients
For the Sesame Tuna: - sashimi-grade tuna, 1 block - 1 part light soy sauce, 1 part apple vinegar, enough to cover a shallow dish the size of the tuna - dash of sesame oil - freshly ground salt and pepper - sesame seeds to coat For the Lime Mash: - 3 floury potatoes - zest of one lime - freshly ground salt and pepper - olive oil For the roasted garlic dressing: - 2 cloves of garlic, skin on - 2 knobs of ginger (about the same amount as the garlic) - red chillies, to taste - freshly ground salt and pepper - dash of sesame oil - dash of apple vinegar - 150ml each groundnut oil and olive oil - juice of one lime
Instructions
This dish made a great summer-tasting dinner, but it was substantial enough to feel nice and full afterwards. The lime mash was something I dreamed up on the train - it works really well with the clean taste of the sashimi tuna. Serves 2. Prepare the dressing: 1. Dry-fry the garlic cloves until they are blackened slightly. Squeeze out the garlic pulp into a blender. 2. Add the ginger and chillies. Blend. Add the liquid ingredients, blend and season to taste. Save in the fridge - this makes more than enough to last you for several dishes. Prepare the tuna: 1. Pour the soy sauce, apple vinegar and sesame oil into a shallow dish. Lay the tuna on the liquid, cover and put in the fridge. Allow half an hour (or more if you have time) then turn and put back in the fridge. 2. Once the tuna is marinated nicely, drain the liquid off. Season the tuna with salt and pepper. Sprinkle liberally with sesame seeds, to cover the tuna completely. Pat down to secure the seeds on the flesh. 3. Wrap the tuna in cling film tightly so the seeds are compacted in further. Put in fridge for at least another half hour. You can store the tuna in the fridge like this and take it out just before you want to cook it. 4. Heat a griddle pan with a little oil until hot. Flash the tuna on each side for literally just a few seconds, creating a cooked border of white flesh running a few millimeters deep all the way round. Use flat-faced tongs so you don't rub off too many seeds. 5. Let the tuna rest for 5 mins. Slice thinly and serve. For the lime mash: 1. Boil the potatoes in salted water until you can poke a fork through easily. Drain and put back in the hot pan to let more moisture evaporate. 2. Mash the potatoes together with a generous lubrication of olive oil. Season with salt and pepper to taste and add the lime zest. 3. To serve, run the biggest spoon you have under a hot tap for a few seconds. Shake dry then scoop the mash like you would ice cream, to form an elongated egg-shape of mash. This is a quenelle and it is a pleasant way of serving mash whilst preserving some aesthetic standards. **And that's it! Plate the tuna and mash with something green - I used baby asparagus. Drizzle with the roasted garlic dressing. Done.**