Puff pastry with savory custard and onions

A roll of puff pastry plus egg and milk or just egg white for brushing

for the savoury custard (recipe by Luca Montersino)

200 g of milk
50 g of cream
60 g of egg yolks
50 g of grated parmesan or grana
9 g corn starch

9 g rice starch
nutmeg
20 g of butter
q.s. of salt

For the caramelized onions:

• 2 red onions
• 1/2 tablespoon brown sugar
• 2.5 cl ofbalsamic vinegar
• a small knob of butter
• salt

If you use the ready-made puff pastry roll, simply unroll it and place it on the baking tray with the baking paper. Prick the base with the prongs of the fork and braid the edge, as I did (watch the reel on IG), brush the edges with beaten egg and milk or egg white and bake following the cooking instructions on the package.

You can prepare the custard up to two days in advance and store it in the refrigerator.

Pour the milk into a saucepan and bring to the boil
Meanwhile, in a bowl, mix the starch with the parmesan, season with salt and nutmeg. Add the cream (not hot) and mix. A dry mixture will form. Pour everything into the boiling milk, mix with a whisk until the mixture has thickened well.
Once the right density is reached, add the egg yolks and continue mixing for a minute.
Remove from the heat and add the butter until it melts.
Quickly cool the cream in a bain-marie of water and ice and then pour it into a porcelain or glass baking dish, cover it with cling film and finish cooling in the refrigerator.

Prepare the caramelized onions:

Peel the onions, cut them in half and slice them. Brown them in butter until they are lightly golden. Sprinkle with sugar, add a pinch of salt and let them caramelize slightly, over low heat, for about 5 minutes. Deglaze with balsamic vinegar, let it evaporate completely and continue cooking over low heat for 20 minutes. Remove from heat.

Assemble your savory pie by filling the puff pastry shell with the savory custard and finishing with the onions and aromatic herbs.