Thinly slice the onion. Slice potates thinly as well to shorten cooking time. Soak them in water and drain.
Heat the butter in a pan to melt. Cook the onion over the low heat until wilted. Do not burn them.
Add potatoes, and stir to coat all the ingredients with oil. Add water and soup stock cubes. Cover with a lid and cook over the low heat until the potatoes are soft.
Cool the mixture down a bit, and blend it in a blender until smooth.
Pour the mixture back into the pan. Add milk and heat not to let it boil. Add heavy cream and season with salt and pepper. Cool down in the refrigerator.
The thickness of the soup will depend on the size of onion and potato slices, as well as how long you keep it over the heat. Add milk to your taste if necessary.
It looks good if you serve the soup in a chilled glass or coffee cup. I sprinkled parsley on top.
Story Behind this Recipe
When I was hooked on cooking different kinds of soup, I wanted to try my hand at Vichyssoise, since it's my favorite kind. I tried to make a thick, sweet and delicious soup, and I created this recipe.
Stir fry the onion well, so the soup will be sweet and delicious. If you don't cover with a lid at step 3, the moisture in the soup will evaporate. (If you like thicker soup, you don't need to use a lid.) Vichyssoise is delicious while still hot, but chilling it will enhance the flavours and add to the depth and creaminess from the potatoes.