|Anchovy paste||1 Tablespoon|
|Strained fresh lemon juice||2 Teaspoon|
Spoon the mixture into a pastry bag fitted with a star tube and pipe an egg-yolk rosette onto the center of each bread round.
Set a caper on each rosette and arrange 2 anchovy fillets around it.
When the leg of lamb has roasted its allotted time, transfer it to a large heated platter, and let it rest while you prepare the anchovy sauce.
Strain the contents of the roasting pan through a fine sieve set over a 1-quart measuring cup, pressing down hard on the onions with the back of a spoon to extract all their juices.
Pour the liquid into a small saucepan and add enough chicken stock to make 2 cups in all.
Bring to a simmer over low heat.
In a small bowl, beat the egg yolks, flour and 1 tablespoon of anchovy paste with a wire whisk until smooth.
Ladle 2 or 3 tablespoons of simmering stock into the egg yolks and mix well.
Whisking constantly, pour the yolks into the pan and cook over low heat until the sauce thickens lightly.
Do not let the sauce come near a boil or the yolks will curdle.
Taste and add 2 to 3 teaspoons of lemon juice.
To serve, mound the sweetbreads and kidneys at both the ends and sides of the leg of lamb and sprinkle them with the remaining 2 tablespoons of parsley.
Arrange the sausages and bread rounds attractively on the platter, and present the anchovy sauce in a bowl or sauceboat.