Thanks for posting the recipes VC I will certainly be trying them. What with Domi's recent topic as well, I suggest we do a Samosa Test next month Ray, what say you, shall we see what Chris thinks?
Jamie's pastry was an eye opener and lends itself to a more traditional way of making the pastry casing. Whilst I enjoyed every last mouthful, I actually prefer to use Samosa skins. These are different to Filo sheets though and produce different results.
I am sure that of those restaurants that make their own, some will use filo pastry, you'll be able to tell this when you cut into the pastry as it will flake into many layers and the taste will be more akin to pastry. Some invariably may make their own pastry, but I imagine that many will use ready to use Samosa skins. Only my opinion though.
The ones I have used are actually cut into strips with 45 degree cuts at either end (i.e. they look like elongated parallelograms). But you can also buy skins formed into a circle which you cut in half and used as you would with Jamie's method. The former lends itself to making a perfect triangle with ease and also allows the Samosa to be filled easily, without too much messing around. The pastry is similar to that of Chinese spring roll. It's thin and when cooked forms a crispy skin not too dissimilar to filo but not flaky. When made, the two sides both have two layers of pastry.
Moving forward, I will always opt for ready to use skins if they are available. But filo and homemade will always be an option if all else fails.