You need to begin this by having a little chopping session. First the ginger, which should be thinly sliced then cut into very fine shreds. The garlic needs to be chopped small, as do the spring onions, making sure you include the green parts as well.
Now place a medium frying pan over a medium heat and, when it's hot, add the sesame seeds and toast them in the dry pan, shaking it from time to time until they're a golden brown colour – this takes only 1-2 minutes. Now transfer the seeds to a bowl.
Next add the oils to the pan and, over a medium heat, gently fry the chopped garlic and ginger – they need to be pale gold but not too brown, so take care not to have the heat too high. After that, add these to the toasted seeds, along with any oil left in the pan, then mix in the lemon juice, soy sauce and chopped spring onions.
Now season the fish, spread three-quarters of the mixture over the surface of each skinned side, roll them up quite firmly into little rolls, then spoon the rest of the mixture on top of each roll. All this can be prepared in advance, as long as the fish is kept covered in the fridge.
Then, when you're ready to cook the fish, line the base of the steamer with the lettuce leaves (or foil if you don't have any). Now place the fish on top, cover with a lid and steam over boiling water for 8-10 minutes. Serve with Chinese Stir-fried Rice.
_This recipe is taken from How to Cook Book One and The Delia Collection: Fish. It has also appeared in Sainsbury's Magazine (Guide to Fish Cookery)._