Plea Saj Go (Cambodian hot-and-sour beef salad)

enough lettuce leaves to cover a serving dish
225g/ 8 oz tender beef steak of your choice
2 T. fish sauce
2 T. lime juice
1 t. sugar
1 onion, halved and sliced
4-5 bird's eye chillies, red or green, finely chopped
(bird's eye chillies are extremely hot and spicy. you may use regular chillies to cut down the heat.)
20 chilli leaves (these are hard to find outside Asia; the same amount of mint leaves may be substituted and actually mint leaves give this dish A very refreshing flavour. in fact, i prefer the mint leaves instead.)

cover a serving dish with washed and dried lettuce leaves and set aside.
Grill the stead to taste -- for authenticity you should leave it very rare (or "blue steak" for the Britons.)
As you grill it, catch the juices in a dish. Leave the steak for 5 minutes to settle the juice inside before slicing it VERY thinly across the grains. Again, retaining any juices. (To do this, you must make sure your chopping board is clean. I normally score the board with boiling hot water before placing meat on it.)
Put the steam and all the juices into a mixing bowl, add the fish sauce and lime juice and mix well. add all the other ingredients in turn, stirring once between each addition.
After adding the chilli or mint leaves, turn quickly out on the lettuce and serve while still warm as part of main dishes with steamed rice.