Dissolve the ammonium bicarbonate in two tablesp. of buttermilk, then mix the flour into the rest of the buttermilk until a soft dough is formed.
Add a good pinch of salt and the ammonium bicarbonate, and mix very well.
Turn out on to a floured board or table, roll lightly and cut into 2-in. scones.
Put on to a lightly greased baking sheet and bake in a hot oven (400Â°F. electric; gas regulo 5) for 15 minutes.
Serve hot, split with butter.
Ammonium bicarbonate can be used in place of baking powder, and in the same quantity for small cakes or buns.
Anyone over a certain age may remember the evocative ammonia smell coming from the kitchen on baking days.
The, results are light, crisp buns, but the bicarbonate must first be dissolved in liquid before adding to the flour.