1. Bring stock to a boil. Season chicken inside and out with salt and pepper and add to the pot. Wrap the bay leaves parsley and dill stems garlic and peppercorns in a square of cheesecloth and add to the pot. Return to a boil adjust heat and simmer uncovered until chicken is cooked through about 45 minutes. 2. Remove chicken and let cool. Discard skin and bones and cut meat into bite-size pieces. Set aside. 3. Strain broth into a pot discard sachet and set aside 1 cup broth to make the avgolemono. Bring soup to a boil and add chicken. Reduce heat to low. 4. Place 3/4 cup avgolemono in a stainless-steel bowl and slowly whisk in a ladle of hot chicken stock from the pot. When well combined whisk in a second ladle of hot stock. Slowly whisk this mixture into the soup. Stir in chopped dill. Do not allow soup to boil again. Season to taste with salt. 5. To serve ladle soup into warm bowls and sprinkle with shredded lettuce and scallions. For Avgolemono: 1. Fill the bottom of a double boiler about 1/3 full of water and bring it to a simmer. Combine the lemon juice and flour in a stainless-steel bowl and whisk until smooth. Add the egg yolks and whisk until thoroughly combined. Set aside. 2. In the top of the double boiler (but not over the heat) whip egg whites and a pinch of salt until fluffy. Slowly drizzle the yolk mixture into the whipped whites whisking constantly to maintain the volume. Place over the simmering water and cook whisking constantly until the mixture is light in color fluffy and begins to thicken about 4 minutes. Very slowly whisk in the hot stock. Continue cooking and whisking for another 2 minutes to thicken. Reserve sauce off the stove in the double boiler. Do not reheat or the sauce may curdle. Season to taste with salt and white pepper.