We have prepared an ode to everyone’s favourite vegetable: the humble potato with this potatoes boulangère recipe. And, since there’s no better time than the cooler months to whip out the slow cooker, there’s a method in here for that, too!
- 50 g butter, plus extra for greasing
- 1 Tbsp extra-virgin olive oil
- 3 onions, finely sliced
- Salt flakes and freshly ground black pepper
- 3 garlic cloves, finely sliced
- 1L chicken or vegetable stock
- 6 desiree potatoes (about 1.2 kg)
- 1 small handful of thyme, leaves picked
- 2 Tbsp finely grated parmesan
Preheat the oven to 180°C. Grease a 2-litre baking dish with butter.
Heat the butter and olive oil in a sauté pan over high heat. Add the onion and a pinch of salt, cover and cook for 5 minutes. Stir through the garlic. Turn the heat down to low, cover and cook, stirring every 5 minutes, for 25 minutes. Remove the lid and cook, stirring regularly, for a further 10 minutes, or until the onion is softened. Transfer to a bowl. Add the stock to the pan, bring to the boil and cook for 8–10 minutes until reduced by one-third.
Meanwhile, cut the potatoes into 1mm thick slices, or as finely as you can. Alternatively, slice on a mandoline.
Arrange two layers of the potato slices in the base of the prepared dish, allowing them to overlap slightly. Season with a pinch of salt and pepper. Now add half of the onion, spreading it out evenly, then scatter over half of the thyme. Repeat the process with the remaining potato, onion and thyme, ensuring the last layer is potato. Press down lightly to compress. Little by little add the hot stock so it has time to trickle into the gaps.
Sprinkle over the parmesan, cover the dish with foil and bake for 40 minutes. Remove the foil and bake for a further 20–30 minutes until the potato is golden brown and meltingly tender. Test this by piercing the centre of the gratin with a sharp knife. If it goes in without resistance, it’s ready. Cool for at least 10 minutes before serving.
Slow cooker method
Grease the slow cooker with butter.
Follow steps 2 and 3.
Follow step 4, layering the potato slices, onion and thyme in the prepared slow cooker. Top with the stock, then cover loosely with foil, pressing down on the potato mixture. Cover with the lid and cook on high for 3 hours, or until the potato is meltingly tender and most of the liquid has been absorbed.
Preheat the grill element in the oven. Transfer the potato to a baking dish or use the slow cooker dish. Sprinkle over the parmesan and grill for 4–5 minutes until the top is golden and bubbling. Cool for 10 minutes before serving.
For more potato perfection, check out Justine Schofield’s potato gnocchi recipe – buon appetito!
Recipe from The Slow Cook by Justine Schofield, published by Plum, RRP $39.99, photography by Rob Palmer.