Preheat oven to 220°C. Wash the potatoes with a brush. Cut large potatoes into 4 pieces, small ones in half. Place the potatoes in a baking dish, season with salt, pepper, drizzle with olive oil and toss to combine.
Put the mold in the oven and bake for 50 minutes until done.
Peel and finely chop the garlic, chop the dill. Salt a little dill and garlic and chop together with butter. Add the resulting mixture to the potatoes and mix, return the form to the oven for another 3 minutes. Transfer the potatoes to a serving platter and drizzle with oil from the mold.