Peel and wash the potatoes and cut or slice them into thin slices. Peel garlic and chop finely. Mix oil, chilli powder, garlic, cumin, turmeric and salt.
Put potato slices in the spiced oil and turn them over. First put them in a sieve, then let them drip off on kitchen paper. Place on a baking tray lined with baking paper and bake in a preheated oven (electric range: 225°/ circulating air: 200 °C/ gas: level 4) for 10-12 minutes, turning after approx. 6 minutes. Remove and place on kitchen paper.