Start making at least the day before.
Pour most of the milk in a pan and bring to a boil.
Add the corn starch on top of the remaining milk and let it sink. Stir.
Mix the yolks and sugar. Add the vanilla and milk/starch. Mix well.
When the milk is boiling, pour it slowly into the eggs while whisking all the time. Return the liquid to the pan and bring to a boil on low heat while mixing. Once it’s thickened and started bubbling, boil for 1-2 mins more. Add the butter and whisk it in.
Pour in a bowl, cover the surface with clingfilm avoiding air bubbles. Let cool at room temperature and then refrigerate until fully cool.
Use as is. The cream is rather soft.
Softly whip about 200ml cream. Add the cold creme patissiere and whip until combined. Use immediately or refrigerate.
(find a recipe) Almost the same as creme legere. It also needs to have gelatin added in. Resulting cream is left to set in molds and can be un-molded.
Mix 250ml mandarin juice with sugar to taste. Soak 1.5 sheets of gelatin in cold water. Gently heat the juice until warm enough to dissolve gelatin (but not higher to prevent bitterness). Mix the gelatin in, pour in 6 glasses to about 1/4-1/3. Let set overnight. (1 sheet of gelatin = very soft set; 2 sheets of gelatin = harder set)
Top with creme legere and refrigerate until serving.