Chicken cut into pieces, add salt, RUB with butter and roast.

To make the sauce: in a skillet to dissolve the butter, add the flour and broth. Stir. Add the mustard, vinegar, sour cream, sugar, salt and boil. Take a little gravy, dissolve in it the yolks and add to the bulk. Put the sauce on very low heat, stirring occasionally, until the sauce thickens.

When the chicken is ready, pour the sauce and boil on low heat.