Set the oven at 200C/gas mark 6. Cook the potatoes in boiling, lightly salted water for about 20 minutes till just tender.
Drain the potatoes, then put them in a baking dish. Press firmly onto each potato, lightly crushing them and opening them up.
Season the cream with salt and pepper. Chop half of the dill and stir into the cream. Slice the cheese thickly and break into large pieces.
Tuck the cheese among the potatoes, then pour over the dill cream. Cover with a lid and bake for 25 minutes, then remove the lid and continue baking for a further 20 until the surface is appetisingly browned.