Dilled Carrot Soup

2 tbs unsalted butter
1 large onion, chopped
4 large carrots sliced thin
4-6 cups low salt chicken broth
1 1/4 teaspoons dill seed

Melt the butter in heavy sauce pan over medium heat. Add carrots, onion and dill seed and saute until onion is trancslucent and tender, about 10 minutes. Add 4 cups chicken broth and bring to a boil. Reduce heat and simmer until carrots are very tender, about 35 minutes. Puree with a stick blender. Thin with more chicken broth if desired. Season to taste with salt and pepper.