Toast the cumin and coriander seeds in a dry frying pan over a medium heat until aromatic, then crush with a pestle and mortar.
Mix together the flour, yeast, sugar, salt and toasted spices in a large bowl. Make a well in the centre, add the oil to the well and gradually stir into the flour with enough of the measurement water to form a moist, pliable dough.
Tip the dough out on to a lightly floured surface and knead for 5 minutes until smooth and elastic. Divide into 4 balls and roll out thinly on a lightly floured surface into long oval or round shapes. Prick all over with a fork and arrange on nonstick baking sheets.
Bake in a preheated oven, 220°C (425°F), Gas Mark 7, for 3 minutes. Turn over and bake for a further 3 minutes until golden brown. Serve immediately or wrap in a tea towel or foil to keep warm before serving.