MJF Note: Trying to make thicker version, up cornstarch and add flour. Made 11/4/19 for cream puff filling. It was great

In heat proof quart-sized measuring cup combine milk, vanilla bean seeds and pod. Scald then let steep. Get ice bath ready.

In saucier (no heat) whisk yolks and sugar until they lighten. Whisk in cornstarch (and flour). Remove pod from milk. Pour 1/3 of the hot milk into the egg mixture, whisking continuously. Whisk in remaining hot milk, and place pot on medium heat.

Cook, whisking constantly, until comes to the boil. Reduce heat and let it boil for about 30 seconds, stirring constantly. Remove from heat and gently whisk in the butter and vanilla. Set in ice bath whisking only occasionally. Place plastic wrap right down on the surface, and chill completely. This can be made up to 3 days ahead.

Another recipes method: BEAT yolks well in medium bowl; gradually stir in milk until blended. MIX sugar, cornstarch and salt in large heavy saucepan. GRADUALLY stir in a small amount of milk mixture, making a smooth paste. Gradually stir in remaining milk. COOK over medium-low heat, stirring constantly, until mixture thickens and comes to a boil, 20 to 25 minutes. BOIL and stir 1 minute. REMOVE from heat. COOL quickly: Set pan in larger pan of ice water. STIR occasionally for a few minutes to hasten cooling. PRESS piece of plastic wrap onto surface prevent skin from forming. REFRIGERATE at least 1 hour.

Insider Info: Use low heat, a heavy saucepan, constant stirring and patience. It takes at least 20 to 25 minutes for the pastry cream to thicken. Increased cooking temperature, the mixture is likely to curdle. Stir constantly, cover the entire bottom and the corners of the pan, ensures that the mixture heats evenly. Check for bubbles: Its hard to see the first signs of boiling. When you feel a heavier drag on the spoon, start lifting the spoon up occasionally to check if any large bubbles are bursting at the top of the mixture. Keep cooking and stirring until large bubbles appear. Then boil and stir for 1 minute. Cool quickly in ice water bath to stop the cooking quickly. Have ready in advance. At this point it is important to stir only occasionally, not constantly. Too much stirring will break down the structure of the thickened pastry cream and result in a thin consistency.