Karoo lamb with potato and onion cake

Karoo lamb with potato and onion cake. Image supplied by Alexis Haden.

Karoo Lamb with Potato and Onion Cake shows how ‘local is lekker’!

A succulent piece of Karoo lamb can be comfort food at its best, and even more so when roasted with savoury layers of potato and onion.

Karoo lamb with potato and onion cake

Karoo lamb with potato and onion cake. Image supplied by Alexis Haden.

South Africa has some of the best lamb in the world. It’s great on the braai and just as good as a roast, but this recipe of Karoo lamb is the ultimate in comfort food.

Karoo lamb with potato and onion cake

5 from 2 votes
Recipe by Petrus Madutlela Course: DinnerCuisine: GlobalDifficulty: Moderate
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This recipe requires very little effort once you’ve done the prep and is perfect for the cooler nights as we head into summer. Roasting the lamb on top of the potatoes means they soak up all the delicious juices and flavours.


  • 400 g 400 floury potatoes, sliced

  • 100 g 100 melted butter

  • a few sprigs of thyme

  • garlic, minced or finely chopped

  • 200 g 200 white onions, sliced (you can mix up red and white onions if you want)

  • a lamb rack (with about six to eight bones each), French trimmed and scored fat


  • Start off by heating the oven to 180°C. Layer the sliced potatoes and onions in a buttered tray. Start with potatoes at the bottom and keep layering with onions and potatoes.
  • Between each layer, drizzle a bit of butter and add some thyme and garlic. If it’s easier, you mix the thyme, garlic and melted butter together first.
  • Remember to season the layers with a little bit of salt and pepper. Continue building the layers until you have used up all your potatoes and onions. Cover the tray with foil and put the oven to cook for 30 minutes.
  • While your potatoes are cooking, season your lamb with salt and pepper, focussing on getting the salt and pepper into the scores on the fat. You can add a little bit of finely chopped rosemary if you like.  Sear your lamb in a pan on the stove, on high heat. Get the fat on the lamb golden and crisp. Once seared on all sides, set aside.
  • After the potatoes have cooked for about 30 minutes, remove the foil and place the lamb on top with the fat up. Cook for a further 20-40 minutes, more or less, depending on how well-done you like your lamb cooked and how big the rack is. A roast timer is a useful tool.
  • Once the lamb is cooked, remove it from the potatoes and cover it in foil to rest.
  • Serve with mustard and a helpful of the potato and onion cake. Add some green beans or asparagus, as a side dish, if you like.
  • The more adventurous can tackle this recipe on the braai
  • Follow the same process as above for the preparation, but use disposable foil container for your potato and onion cake. Sear your lamb on the open coals and then transfer to the foil container to catch the juices while it cooks.

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Find the perfect side to compliment this succulent meal. Head over to our recipes section to select a suitable side to suit your tastebuds.