- 2 tbsp olive oil, plus extra to grease
- 3 large onions, finely sliced
- 1½ tbsp wholegrain mustard
- 2 tsp dried thyme
- salt and ground black pepper
- 1,5kg floury potatoes
- 600ml double cream
- 400ml full-cream milk
- 2 large garlic cloves, crushed
- handful fresh white breadcrumbs
1. Heat the oil in a large pot and gently cook the onions, covered, for 15 minutes until completely soft. Stir occasionally to make sure they aren’t catching – add a few drops of water if they are. Stir in the mustard, thyme and some seasoning; transfer to a bowl.
2. Preheat oven to 200°C and thoroughly grease a 3 ovenproof serving dish (not too deep). Peel the potatoes and slice into 3mm rounds – a mandolin is helpful for this. Put the potato slices into the empty large pot with the cream, milk, garlic and plenty of seasoning. Bring to the boil.
3. Pour potato mix into the prepared dish and level the slices as much as possible. Top with onion mix and cover with foil.
4. Cook for 45 minutes, then take off foil, scatter over breadcrumbs and return to the oven, uncovered, for about 25 minutes or until golden and the potatoes are completely tender. (Test by pushing a knife into the mixture – it should go through easily.) Serve immediately.
EACH SERVING About 2 560kJ, 8g protein, 46g fat (27g saturated), 40g carbohydrate (8g sugars), 5g fibre.
GET AHEAD Prepare to end of step 3 up to 3 hours ahead. Leave at room temperature. Complete recipe to serve.