1. Boil 1 quart water in large saucepan. Remove from heat, add corn cobs (after corn has been removed) and let stand, covered, 10 - 20 minutes.
2. In 4-quart soup pot, saute onion in olive oil over medium heat until onion is translucent (about 8 minutes). Add potatoes, thyme, nutmeg, salt and pepper and cook, stirring, 5 minutes.
3. Remove cobs from water and discard. Pour water over corn and potatoes and bring to a boil. Reduce heat, cover, and simmer until potatoes are tender.
4. Adjust seasonings to taste. Remove 2 cups of solids from the soup and reserve. Puree soup in a blender or with an immersion blender. Add reserved solids.