Low-carb short-crust pastry - first attempt

I've been meaning to have a go at inventing a pastry recipe for ages.  Last night I had a try, and the results were surprisingly succesful  There's room for improvement, texture-wise, and it isn't gluten-free; but it is high-fibre and low-carb (about half the carb load of regular pastry) and it made a perfectly acceptable shell for a quiche, so overall I feel that's a good start.

Ingredients

3 oz/ 75g/ 3/4 cup No 1 baking mix (recipe for that is here)
3 oz/ 75g/ 3/4 cup wholemeal flour (I'm using spelt at the moment as I like the flavour)
3 oz/ 75g butter
Cold water

Method

Method starts pretty much as normal.  Seive the flour, mix thoroughly with the baking mix and rub in the fat quickly and lightly till the mixture resembles breadcrumbs.  Add enough cold water, splash by splash, to bind the mixture together and gather it into a ball.

This is where things stopped being normal.  The lack of gluten in the baking mix meant the dough didn't have the same ability to stick together as a regular short-crust pastry would.  It took more water than a regular pastry recipe before I has a mix that would bind at all.  But then the very different kind of stickiness of the milled linseeds in the baking mix started to react to the water, and the dough suddenly became quite odd in texture - the least-unpleasant word I can find for it is slippery - and turned a rather unappetising greyish colour.

I looked at this and thought various less-polite forms of "oh bother".

I'd already prepared my quiche filling (1 onion, cooked in a little veg oil, mixed with 1 chopped fresh tomato, 2 eggs, 3 oz/ 75g grated strong cheddar, some milk, salt and pepper and 1 tsp wholegrain mustard), so I figured I'd better do my best with this mixture, and try again another time to get something that looked and behaved more like conventional short-crust pastry.  I was anticipating eating something leathery in the extreme, though.  Still, all food is food (sometimes in the world of experimental cookery you have to say this to yourself!).

I slapped a sheet of baking parchment into the tin, in case that rather wet mixture decided to stick, and then I tipped the mixture onto this, and smoothed it out and pushed it up to the sides by hand.  As the linseeds continued to absorb more of the moisture, the mixture seemed to grow stiffer and less slimey, and I was able to get a rather rough and untidy-looking case shaped.  I poured in the filling, topped it with a bit more grated cheese and stuck it in the oven at 150 degrees C (it's a fan oven by the way).

35 minutes later I took it out, and discovered that despite my worries I'd produced a perfectly succesful, robust, tasty pastry case.

I'd eaten half before I thought to take the photos...

Because the pastry was rather wet and slippery when made, I can't see how this would work for the kind of recipes where it needs to be rolled out and cut. I need to work out how to arrive at a result that is firm and holds its shape enough to treat conventionally like that.

But until it came out of the oven I fully expected to end up with a supper that tasted as if it was made of plasterboard.  So to end up with a pastry case that was crisp and flavoursome, kept its shape, and held a standard quiche filling without leaking, pleased me no end.

I'll be working on improvements to the texture and will report any successes here.