On medium heat, melt butter and simmer onion and celery for 5 minutes until soft, but not brown.
Add water, potato, corn and seasonings. Cover and simmer for 30 minutes or until potatoes are barely tender.
Whisk the flour into 1 cup of the half and half and stir into the soup. Add the remaining 3 cups of half and half. Simmer for about 15 minutes until the soup has thickened to a creamy consistency.
Correct the seasoning with additional salt and pepper, if needed. Correct the consistency, if needed. To make the soup thinner, add a little milk. To make the soup thicker, simmer another 5 to 10 minutes.
Makes: 4