Ingredients:
400 gm of home-made shortcrust pastry (or 1 roll of pre-made shortcrust)
600 to 700 gm of finely sliced onions.
150 gm of butter (100 gm to cook the onions and the rest after adding the Béchamel)
salt and pepper to correct the seasoning at the end
1 or 2 tbsp of heavy whipping cream (double cream) 37% fat content
For the Béchamel:
60 gm butter (for the roux)
60 gm plain flour (for the roux)
500 ml whole milk (full cream)
1 tsp of salt
1 pinch of black pepper
2 or 3 pinches of grated of nutmeg
1 small bay leaf
Note: The shortcrust pastry must be blind-baked before it can filled with the Béchamel mix.
To process the onions with the Béchamel you will need a stick blender or a food processor.