Rub together flour, butter and sugar till sandy texture. Sprinkle just enough water to make into a dough. Cover with a damp cloth and keep in refrigerator for 15mins.
Take out the dough and using dry flour roll out into thin sheets (approx 3mm). Place this dough over tart moulds and press gently to cover the mould. Trim the sides for a neat shape. Prick with a toothpick or a fork. Now place these moulds in a pre heated oven at a temp of 180c for 12-15 mins. Remove and allow to cool completely.
Place the nuts in a tray and light roast them in a oven for 8 mins at a temp of 150c. Remove and break them roughly.
Separately place sugar in a pan and on very slow heat let it caramalise. Once the sugar is light golden remove from fire and add butter and mix quickly. Now fold in the nuts. Adding butter to sugar makes it gooey and easy to fold. Spoon this mixture into the tarts. Serve these beautiful tarts at room temp. Do not refrigerate.