1.) In a large saucepan, SEASON the stock with salt and pepper and BRING to a simmer.
2.) TRANSFER 1 cup of hot stock to a blender. ADD 1/2 cup of the cooked rice, egg yolks, whole egg and lemon juice and PUREE until smooth.
3.) STIR the puree into the simmering stock along with the chicken and the remaining 1 1/2 cups of rice, cooked butternut squash, mushrooms and kale, and SIMMER until thickened, about 10 minutes.
4.) ADD to bowls and TOP with an extra squeeze or two of lemon juice and fresh ground black pepper.