In a bowl, place the ground beef with the rice (which we have rinsed out a couple of times), the onion, parsley, one of the egg whites, a sqeeze of lemon juice, salt and pepper. Knead this mixture well.

Set the butter to melt in a saucepan.  Having formed the mince mixture into dumplings, approximately the size of a walnut, place them carefully into the saucepan.  Pour in enough water to cover the dumplings.  We can add more water than that, for even more tender dumplings.  Let them simmer over a medium heat, till done and we are left with as much liquid as we desire.

Whisk the 2 egg yolks and remaining egg white with the rest of the lemon juice.  Add spoonfuls of the dumpling liquid as you continue whisking, so as to temper the sauce.  Pour the lemon-egg sauce over the dumplings in the pot.

Gently twirl your pan from side to side, over a low heat, to distribute and thicken the sauce.