Preparation:

Rub the flour, the salt, 100 g of grated cheese and the margarine together until you get a crumbly mix. Add the egg and the soured cream. Knead together. Roll out to a thickness of 2 cm (or an inch, which is a bit thicker). Using a knife, score a lattice pattern into the top of the rolled pastry. Using a pastry cutter (or a small drinking glass), cut circles from the dough. The cut-off bits can be kneaded together and rolled out again to reduce waste. Sprinkle the top of the dough medallions with the other 100 g of grated cheese, and bake in an oven (190-200C) for about 15-25 minutes. Electric ovens work faster. Don't overbake.

Instead of the grated cheese topping, you can sprinkle it with caraway seeds, in which case you need to brush the tops with egg first.