Heat the oil in a frying pan, add the lettuce, fry for approx. 2 mins., turning occasionally, then remove. Add the onion to the same pan, along with all the other ingredients up to and including the sweetcorn, stir fry for approx. 2 mins., pour in the stock. Return the lettuce to the pan, cover and simmer for approx. 5 mins.
Prepare the falafels according to the packet instructions, serve with the baby lettuce.