Onion tart with soubise filling

Peel the onions and process them in a food processor; make and blind bake the short crust ahead.

Blanch the onions: put them in a pan of cold water and bring to the boil to take away their sharpness.

Melt the butter over very low heat, add all the flour at once and cook the roux 3 minutes, until it smells like cake.

Off the heat dilute the hot roux with some of the cold milk to avoid clumps, then add the rest.

Return to medium heat; at a light boil add salt, pepper, a little bay leaf and a grating of nutmeg. Leave on very low heat 5 to 10 minutes until very thick.

Boil the onions a good 5 minutes, drain, rinse in cold water and press out as much water as possible.

Melt the onion butter in the same pan on low heat, add the onions and coat well; season with a pinch or two of salt, a little black pepper and a pinch of sugar.

Cook covered on very, very low heat for 40 minutes until they turn into a soft puree.

Off the heat incorporate the thickened bechamel in batches, then the rest of the butter, and mix.

Blend with a stick blender instead of passing through a drum sieve; add water to dilute until very white and smooth.

Over medium heat stir in a good tablespoon of cream and correct salt and pepper; optionally more nutmeg or a little cayenne.

Cook a further 15 minutes on low heat.

Fill the blind-baked crust to the top and sprinkle with breadcrumbs.

Bake 15 minutes at 220 degrees (Celsius; the Fahrenheit equivalent is shown on screen).

Rest until lukewarm or room temperature so the bechamel sets before slicing.