In a heavy 3 to 4 litre saucepan over moderate heat, melt butter. Stir in onions and cook 5 minutes. Add carrots, stock, tomato paste and rice. Simmer 30 minutes. Puree in blender in small batches until smooth. Return to pan. Add salt and pepper and stir in cream. Simmer for 10 minutes; stir in softened butter. Garnish with carrot curls. Colorado Cache Cookbook (1978) From the collection of Jim Vorheis