Preheat the slow cooker if necessary; see the manufacturer's instructions. Heat the oil in a frying pan, add the onion and fry, stirring, for 5 minutes or until just beginning to turn golden.
Stir in the garlic, paprika, dried chillies and peppers and cook for 2 minutes. Mix in the tomatoes, stock, thyme, olives and some salt and pepper, then bring to the boil.
Add the potatoes to the slow cooker pot, pour over the hot tomato mixture, cover with the lid and cook on high for 4–5 hours or until the potatoes are tender. Serve with warm crusty bread and a dressed green salad, if liked.