1Chop onion and celery in bite size pieces. Slice leeks and put into water and let them float to the top. The dirt will settle at the bottom. Remove leeks from water with sieve.
2Saute celery, onion and leek in melted butter for 5 minutes. Add potato to pot and pour in vegetable stock. Make sure that the stock covers the potatoes and vegetables by about 1/2 inch. Add spike now if you are using it.
3Cook potatoes and vegetables for 15 minutes, or until potatoes are soft. Add salt and pepper when vegetables are soft. Using either an emersion blender or potato masher, puree vegetables until somewhat smooth but still has potato chunks in it.
4Remove from heat and let sit for 5 minutes, then slowly stir in half & half. If you add half & half right when you take it off the heat it may split. Pepper to taste and serve.