Break up peas; place in saucepan with butter.
Add water chestnut liquid, stock base, ginger and nutmeg.
Simmer, covered, over low heat until peas are bubbling hot.
Blend cornstarch and water; stir into peas.
Cook slowly, stirring constantly, until liquid thickens and boils.
Add water chestnuts.
Simmer 2-3 minutes longer