Carrot-Dill Soup
["1 medium sweet potato", "1 baking potato", "12 medium carrots, thinly sliced", "2 Tbsp. minced fresh dill", "5 c. chicken stock or canned broth", "1 1/2 tsp. salt", "1/4 tsp. freshly ground pepper", "1 Tbsp. fresh lemon juice", "2 Tbsp. unsalted butter", "sour cream", "1 small onion, chopped"]
["Bake the potato and sweet potato 1 hour until soft.", "Steam the carrots over boiling water until very tender (8 to 10 minutes)."]
["sweet potato", "baking potato", "carrots", "dill", "chicken", "salt", "freshly ground pepper", "lemon juice", "unsalted butter", "sour cream", "onion"]