Heat the oil in a large pan, add the onion and cook gently until tender.
Add the meat and fry for 5 minutes, until browned.
Stir in the wine and some salt and pepper, then cover and braise for 20-30 minutes, until the lamb is tender, stirring occasionally to prevent sticking.
Lightly beat the whole egg and egg yolks in a bowl, then add the parsley and lemon juice. Take the pan off the heat and pour in the egg mixture, stirring to obtain a silky-smooth sauce; the heat of the meat will gently cook the eggs but they should not scramble.
Cook the asparagus stems in simmering water until they are soft (or they can be steamed).
Serve the lamb immediately, with some ciabatta bread and some asparagus.