*Often coconut milk will have separated into a solid of white cream and a watery liquid. If yours has done this, pour the thin liquid into the pan and whisk the cornstarch in before adding the cream. If you add it all at once, the little bits of white cream look exactly like chunks of cornstarch, so it's hard to know if the cornstarch is all whisked in. If in doubt, whisk for a good long minute and you should be safe. If you do end up with chunks of cornstarch (I doubt it), just strain when the syrup is finished.