Place the chicken in a low, wide saucepan. Add the onion, salt, garlic, half the dill, chicken stock, and wine. Bring to a boil over high heat, then lower the heat and simmer for 20 minutes. Remove the chicken pieces from the liquid and place them in a baking pan in a 300° oven while preparing the sauce.
Skim the fat off the liquid in the pan, then reduce over very high heat by one-half