Substitute for Fresh Cream

Take 1 tablespoonful of cornflour, mix to stiff paste with cold water, then add three quarters of a cupful of boiling water; leave stand until quite cold. Take one heaped tablespoonful of butter and a bare tablespoonful of sugar, beat to a cream; then add cornflour, teaspoonful at a time, till all is used; beat for 15 minutes.