Borettane onions are also excellent when used to prepare savoury tarts. Here is a suggestion for a tasty tart, enhanced by the sweet flavour of Borettane onions.
1) Prepare a dough with 250g of flour, 2 whole eggs, 4 spoons of Evo oil and 2 spoons of cold water. Mix well and work the dough until you obtain a firm and elastic ball; wrap it in a dishcloth and keep in the fridge until needed.
2) Stew 500 g of Borettane onions in an ample anti-stick pan with a lid, adding 20 g of butter, 50 ml of white wine, salt and pepper. Cook for 15 minutes, stirring often.
3) Grease and flour a 22-cm round cake tin, roll out the dough in it, rolling the rolling pin along the edges in order to level off the surface and remove the excess (you will need it for decorating). Pour the cooked onions in the tin and make a grid with dough strips; seal the tart edges well. Cook in the oven at 180°C for 35 minutes.