In a medium saucepan, melt the butter & cook the scallions over medium heat a few minutes or until translucent. Add 2 1/2 cups chicken broth and bring to a simmer, cook for 3 minutes. Cut open the avocados, discard the pit and put them in a food processor with the other 1/2 cup of broth and the cream. Blend until smooth. Add the avocado mixture back to the pan and let simmer for 3 minutes. Season with salt and pepper. YUM!