Lemon Sauce

Directions

1. 1
   Heat chicken broth and butter in a heavy saucepan.
2. 2
   Blend cornstarch with water in a small dish until smooth.
3. 3
   Slowly stir mixture into chicken broth.
4. 4
   Cook, stirring constantly, over low heat for 5 minutes, or until broth is thickened and smooth.
5. 5
   Beat 2 tbsp broth into egg yolk, then stir yolk mixture back into the broth.
6. 6
   Add lemon juice and zest, cook 1 minute longer.
7. 7
   Do not allow the sauce to boil.