About this recipe:This soup is known in France as Potage Saint-Germain, a name that comes from a suburb of Paris where peas used to be cultivated in market gardens. If fresh peas are not available, use frozen peas, but thaw and rinse them before use. Croutons make an excellent garnish!
Melt the butter in a heavy-bottomed saucepan over medium heat. Cook the shallots until soft and translucent, about 3 minutes. Pour in the water and peas, season to taste with salt and pepper. Increase the heat to medium-high, bring to a boil, then reduce heat to low, cover, and simmer until the peas are tender, 12 to 18 minutes.
Puree the peas in a blender or food processor in batches. Strain back into the saucepan, stir in the cream if using, and reheat. Season to taste with salt and pepper before serving.