I’ve given quantities for four here as it makes sense to cook extra for the next day. Be very careful with the eggs - don’t boil the braise once you’ve added them.
Heat the oil in a heavy bottomed pan and brown the lamb on all sides. Do this in batches – it browns better like this – and remove each batch with a slotted spoon as you do so. Set the lamb to one side.
Cut the heads of the cos lettuce across the ways into strips, discarding the base of each one.
Add the onions to the pan and cook in the fat left over from the lamb over a medium-low heat. The onions should be soft but not coloured.
Now add the spring onions and the lettuce and cook gently for another 4 minutes or so.
Put the lamb back in the pan, together with any juices that have run out of it, plus half the dill. Season well.
Add enough water to just cover the meat, bring this to a simmer then cover the pan and cook gently for an hour. Take the lid off the pan and, if there is slightly too much liquid – if the lamb is swimming in it - leave the lid off and continue to cook for another 30 minutes. (If there isn’t enough liquid then put the lid back on again). The meat should be cooked to a melting tenderness in 1 ½ hours but check – you may need another 15-30 minutes on top.
Whisk the eggs and lemon together in a bowl. Ladle some of the warm broth from the stew into this and mix well, then add this to the stew and stir it in. Continue to heat slowly, cooking for about 3-5 minutes. The eggs and lemon will thicken the juices. Don’t allow the mixture to boil or the eggs will scramble.
Check the seasoning, stir in the rest of the dill and serve. Rice is the perfect accompaniment.