Mix the chia/flax seeds and water together in a bowl, and set aside whilst they turn 'gloopy'.
In a large bowl, mix the flour, baking powder, salt, sugar, and cayenne pepper. Cut the margarine into cubes, then rub it in to the flour until the mixture resembles fine breadcrumbs.
Add to the chia/flax seeds the yoghurt, mustard, garlic, sun-dried tomatoes and pine nuts, and pour this mixture in to the dry ingredients, mix with a knife and bring together into a soft dough. Do not over-knead, just mix until everything is combined.
Tip the dough onto a floured surface, and roll out into a rough rectangle shape about 2-3cm thick. With a sharp knife, cut the rectangle into three equal pieces, then cut each diagonally across to form 6 triangles. Place these on a baking sheet covered with baking parchment or greaseproof paper, and brush the tops with a little soya milk.