Dilute the yeast in a little warm water. Put the flour and salt into a bowl, add the diluted yeast, and slowly add enough water to the flour until the mixture forms soft dough. Knead well and then leave to rest overnight.
Boil the potatoes for 5 minutes, leave to cool, then cut into quarters.
Heat the oil and butter together in a frying pan over a moderate heat and fry the potatoes and garlic, until the potatoes are golden, then leave to cool.
Lightly grease a baking tray. Divide the dough into two pieces and flatten them into an oval shape. Place on the baking tray and leave to rise for 1-2 hours.
Set the oven to 450°F Cover the two pieces of dough equally with the potato mixture, pressing it in firmly. Sprinkle with chopped dill and bake for 25 -30 minutes until golden brown. Transfer to a wire rack to cool.