Sage and onion potato rostis


I think potatoes are one of the most wonderful food stuffs known to man. So versatile, delicious and a great source of fibre and antioxidants. I’m an absolute sucker for them in almost any form- mash, jackets, big chunky chips, wedges, mash…. Wait, had I said mash already? I really can’t think of a single form of potato that I don’t like. 

But I definitely do have my favourites and these have quickly pushed their way into that category. Rostis are always delicious but with the addition of some white onion, sage (fresh or dried) and garlic granules, I think these are really tasty.   

Personally I love the deep and woody flavour of sage but if you don’t, you could definitely try other herbs. I have a seemingly endless list of recipe modifications and experimentations that I want to try. As far as these rostis are concerned I want to try them with thyme, maybe even some basil and oregano for a Mediterranean twist. I also want to try adding just a little grated cheese into the rosti mix – so many variations and so little time to getting round to trying them all!

When you are making these and forming the actual rostis to put into the oil, the potato mix feels quite loose. It will feel like they’re not going to hold together at all – and you will definitely lose a few bits. The key thing is to handle them confidently but carefully. Once they are in the oil leave them to cook on one side for 5 minutes, as stated in the recipe, without trying to move or adjust them. When they have cooked like this on one side they will be a lot more robust and stay together better (although it may not feel like it when you’re turning them). It helps to have a decent heatproof spatula or fish slice. These are a must have for your kitchen if you are doing any amount of cooking. If you are just starting out and don’t really now what you’re looking at or are just looking to replace your existing utensils there is an amazing and positively customer rated set which literally seems to include anything a cook would ever want or need and at such a good price. Have a look here!

I’ve found these rostis to be a pretty versatile side – they work equally well as part of a fry-up with bacon, eggs and beans or with a piece of griddled salmon and some steamed vegetables as part of a slightly more sophisticated and waistband friendly dinner. 

Let me know what you think, what you serve them with or if you make any changes that you’re really pleased with in the comments or by using the contact me form on the site. Enjoy! DDx

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Sage and onion rostis

  • Author: Hazel
  • Total Time: 25 minutes
  • Yield: 4 rostis 1x


Golden crispy potato rostis with onion and fresh sage – enjoy as part of a fry up or as a side to some fish!


Units Scale
  • 400 g potatoes
  • 1 egg, beaten
  • 1 teaspoon plain flour
  • 1/4 teaspoon baking powder
  • 1 white onion, finely diced
  • 5 sage leaves, finely chopped OR 1 tablespoon dried sage
  • 1 teaspoon garlic granules
  • 2 tablespoons vegetable oil, for frying


  1. Grate the potatoes (using the coarse side of your grater) directly onto a clean tea towel. Roll up the towel, hold over the sink and squeeze as much moisture as possible out of them.  Tip the potato into a bowl and mix well with the egg, flour, baking powder, onion and sage. Season well. 
  2. Heat the oil in a large non-stick frying pan over a medium heat.  Shape the potato mix into 4 rostis and very gently flatten them down to make them disc shaped. Put each one a fish slice or spatula and slide off gently into the hot oil – at this point the rostis will look like they won’t hold together – you will lose a few bits during cooking and turning but they will hold together much better as they cook so don’t worry!
  3. Cook for about 5 minutes on each side or until golden brown and crisp.
  4. When cooked, drain on a plate lined with kitchen roll briefly before serving.
  • Prep Time: 15 minutes
  • Cook Time: 10 minutes


  • Serving Size: Per rosti
  • Calories: 203.4kcal

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