Jamie Oliver's Asian Infused Tuna takes about 10 minutes to put together, involves no cooking, and makes your guests go all squidgy on you. Here's how it goes:

Pile together in a large bowl (this serves 6-8 as starter) the following:

11b/450g tuna (bluefin if possible), diced into small chunks
1 ripe avocado, peeled and diced
Juice of 4-5 limes, to taste
1-2 fresh red chillies, deseeded and finely chopped (to taste)
3 tablespoons sesame seed oil
4 tablespoons coconut milk
1 good handful fresh coriander, finely chopped
2 heaped tablespoons sesame seeds
Small finger-sized knob of fresh ginger, peeled and finely chopped
Soy sauce to taste (I like quite a lot, others may like less salty).

Mix 'em all together, and serve on thinly sliced ciabatta bread that's been cooked in a hot oven for 15 minutes with a bit of olive oil drizzled on top. Yum.