Yet another Corn Chowder

4 cups (1 liter) corn kernels, cut from 8 large ears
2 medium-sized potatoes, cut into 1/2 inch (1 cm) cubes
1 small Bermuda onion, finely chopped (1 cup [1/4 liter])
2 1/2 cups (625 ml) water
2 cups (1/2 liter) chicken broth
5 tablespoons (75 ml) butter
2 cups (1/2 liter) hot milk
salt and coarsely ground pepper
cayenne pepper
1 cup (1/4 liter) heavy cream

Place the corn in a large (4 quart (4 liter) saucepan.
Pour in 1 cup (1/4 liter) of the water, and the chicken broth.
Place on low heat, bring to a boil and simmer for 15 minues.
Stir occasionally.
In the meantime, boil the potatoes in the remaining 1 1/2 cups (375 ml) of water until tender, or for about 15 minutes.
Drain.
Gently cook the chopped onion in 4 tablespoons (60 ml) of the butter, without browning, until soft (about 10 minutes).
Add the onion, well-drained potatoes and hot milk to the corn.
Puree this mixture in a blender, a cup or two (1/2 liter) at a time, running for 1 minute at low speed and another minute at high speed.
Place the puree in the top of a very large double boiler.
Season to taste with salt and pepper and a dash of cayenne.
Place the pot over boiling water and heat the soup thoroughly.
When the mixture is scalding hot, stir in the heavy cream.
Place the remaining tablespoon (15 ml) of butter in a soup tureen, pour in the chowder and serve at once.