If you cooked the pudding mix on low heat for 10 to 15 minutes you would not get corn starch taste. To get the corn starch taste out, simmer cook the mix until it’s thickened enough. Do not get tempted to speed up the process by cranking up the heat to cook faster. High heat will ruin the pudding, eggs will scramble and corn starch will not be cooked enough and you get corn starch taste in it.