Smashed Roast Potato and Thyme Gratin

Total Time
Prep 15 mins
Cook 30 mins

A budget-saving recipe for using leftover roast potatoes. You could also use leftover pumpkin, kumara and califlower or a combination of these or other leftover vegetables. This gratin matches well with reheated leftover roast meat or with a savoury ground meat dish or with sausages, such as Garlic and Rosemary Stuffed Sausages or Crumbed Pork Sausages With Coleslaw. If you prefer vegetarian dishes, simply omit the bacon. This is on of several recipes I've adapted from one in 'The Australian Women's Weekly's Cooking on a Shoestring'. I've also posted Potato and Rosemary Pizza and Broccoli and Garlic Breadcrumb Spaghetti.

Ingredients Nutrition

  • 60 g butter (2 ounces)
  • 1 medium brown onion, sliced thinly (150g or just under 5 ounces)
  • 1 leek, white and inner green tender leaves, thinly sliced
  • 2 -4 garlic cloves, crushed
  • 600 g roast potatoes, cut into halves (just over 19 ounces)
  • 2 tablespoons plain flour
  • 1 cup milk (250ml/8 fl.oz. )
  • 2 teaspoons fresh thyme, finely chopped
  • sea salt, to taste (add with caution as the potatoes were undoubtedly salted when first cooked)
  • fresh ground black pepper, to taste
  • 12 cup sunflower seeds (optional)
  • 2 slices rindless bacon, fat removed, chopped
  • 1 cup cheddar cheese, coarsely grated (120g or just under 4 ounces)


  1. Preheat the oven to 220°C/200°C fan-forced/400°F/gas mark 6; oil four 1-cup (250ml/8 fluid ounce) shallow ovenproof baking dishes.
  2. Melt 10g of the butter in a medium saucepan; cook the onion, leek and garlic, stirring, until softened.
  3. Meawhile, use a potato masher to gently crush the potato in a large bowl; stir in the onion, leek, garlic mixture.
  4. Melt the remaining butter in the same pan, add flour; cook, stirring, until the mixture thickens and bubbles; gradually stir in the milk; cook, stirring, until the white sauce boils and thickens; remove the pan from the heat; sir in the thyme and half the cheese.
  5. Stir the white sauce into the potato mixture; spoon the gratin mixture into the prepared dishes; sprinkle each with the chopped and grated cheese.
  6. Bake in the oven for about 20 minutes or until lightly browned and the bacon is crisp.
  7. NOTE: What Australians call a brown onion is what Americans call a yellow onion, and I'm not sure what everyone else calls them. For some reason - though I've done so in the past - I wasn't able to include this in the ingredients.