Rinse the peas in cold water, reserve 1/2 cup of peas for garnish and set to the side.
Melt the butter in a saute pan. Add the shallots and cook until soft. Add the peas, sugar and chicken stock. Bring to a boil and cook until peas are tender.
Strain the peas and shallots. IMPORTANT: SAVE THE STOCK.
Add the peas, shallots, mint and half the stock to a blender. Puree, slowly adding additional stock, until the puree is smooth and not too thick. Season with salt and fresh ground pepper. Transfer to a sauce pan and keep warm until ready to serve. The is good at room temperature too.