I find making it with Sainsbury's full fat coconut milk gives you such a solid Chia pudding that any flavouring doesn't make it runny. I use 3,5 tablespoons Chia to 1 can coconut milk. I've tried other brands but Sainsburys full fat (own brand) is the only one that produces the solid Chia. I stock up with cans any time I'm in as they have a bad habit with deliveries of sending the low fat one and it doesn't work.
Ooh Ive just looked in my cupboard and lo and behold - a can of Sainsbos full fat coconut milk so a bowl of chia pud is now ‘cooking’ in the fridge. You’re right, it is quite solid even from the tin.
I’ve pretty much given up with the low carb pastry. I used a packet for yesterday’s dinner, and as I wasn’t going to eat it anyway I figured that was fair enough, noone else minded. I did decorate the top with pastry leaves etc though.