Firstly, slice the beef into thin strips and place into a bowl with rest of the ingredients for the marinade. Leave for a couple of hours for maximum flavour.
Make the sauce by adding all the ingredients to a saucepan and bringing to a gentle simmer, remove from the heat and leave to cool.
For the fried iceberg lettuce, chop the lettuce into wedges, chop the spring onions into chunks, slice chilli, chop ginger and garlic.
Add sesame oil and a little veg oil to the pan, once hot add the ginger, garlic and spring onions, cook for 30 seconds, add the lettuce, cook for a further 30 seconds before adding the soy, sugar and a splash of water.
Cook the beef under a hot grill for a couple of minutes each side and serve with the dipping sauce and fried iceberg.