Dry the chicken breasts with paper towels

Melt the butter in saute dish

When it froths, add the chick- en

Brown the chicken breasts on both sides and transfer to a warm dish

Keep warm. Add onion and garlic to saute dish, and simmer on low heat until the onion is soft but not browned

Add chicken stock and tarragon, bring to a boil

Return the chicken pieces to saute dish, lower the heat, and simmer until the chicken is cooked, approximately 10 minutes

Transfer the chicken to a serving dish and keep warm

Combine yogurt, cornstarch and egg yolks, stir gently

Slowly add the yogurt mixture to the liquid in the saute dish, stirring continuously

Simmer until the mixture thickens

Season to taste

Serves 4.