Peel, wash and quarter the potatoes. Cook in boiling salted water for about 20 minutes. In the meantime heat oil in a pan and fry the minced meat. Peel onions and garlic and dice finely. Add to the mince and fry for about 5 minutes. Wash the rosemary, dab dry, pluck the needles from the stems and chop.
Season to taste with salt, chilli powder, pepper, thyme, oregano, rosemary and cumin. Drain the potatoes and mash them into puree, adding milk and fat. Season with salt and nutmeg. Spread the minced meat in an ovenproof dish (18 x 30 cm; 1 1/2 litre capacity) and spread the mashed potatoes on top. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 20 minutes. Serve garnished with thyme and rosemary