If you are deciding to use a milk other than whole milk for this recipe, please note that the achieve a custard, you'll want this main ingredient to have at least 12% total fat content.
In a sauce pan, over medium heat, get milk to scalding - just before boiling - so that there are little bubbles along the edges, and steam is coming up. Remove from heat and allow to cool for 10 minutes.
In a separate bowl, combine 6 egg yolks, sugar, and corn starch. Whisk. Pour cooled milk. Whisk together.
Pour these combined ingredients back into the pan and put at medium heat. With a whisk and handheld thermometer, whisk constantly until the mixture reaches 180 degrees.
Remove from heat and pour to cool into a bowl or ramekins - covered for 30 minutes and then chilled for two hours for your custard to completely set. You can enjoy this dessert as-is, or use your oven to torch for creme brulee.