This is a wonderfully easy, forgiving pastry that works equally well as a savoury version or, with a couple of tablespoons of castor sugar added, for desserts and sweet tarts/pies. It's based on Maggie Beer's famous pastry and it ALWAYS works. 

INGREDIENTS

150g butter, well chilled and divided into thumb nail sized pieces
300g plain flour
125g full fat sour cream*
1-2 tbsp iced water
2 tbsp castor sugar (if you're wanting to use the pastry for a sweet pie/tart)

METHOD

In the large work bowl of a food processor place the flour and butter (and sugar if using). Use the Pulse setting to gently work the butter through the flour, processing it until the mixture resembles large breadcrumbs.

Add the sour cream and, again using the Pulse setting, process until the mixture begins to clump together into several 'shaggy' balls. Don't be tempted to keep processing until you have one ball of over-processed dough as the resulting pastry will bake up tough and dry. If your dough is not coming together satisfactorily feel free to add the iced water a tablespoon at a time to help the pastry come together.

Tip the pastry onto a lightly floured bench and quickly and gently bring the pastry together into a large, flattened disc. Cover with plastic wrap and refrigerate for at least 30-60 mins to rest.

Your pastry is now ready to roll out and use for your intended recipe.

* Please do use full fat sour cream, the richer the better for this pastry. Low fat or 'lite' versions won't cut the mustard here I'm afraid.