- Preheat the oven to 180 degrees.
- Remove the onions and cut into 2mm wide strips, and peel the garlic and finely chop.
- Heat the rapeseed oil in a pan, add the onions and garlic and simmer over medium heat with occasional stirring until golden brown.
- Peel the potatoes, cut into small cubes and place in a pan. Bring the cream to a boil and boil the potatoes until firm.
- Cook the Magronen according to the instructions and drain well. Rub the cheese and add half of it with the magrone and the steamed onions to the sauce.
- Boil everything again with salt and pepper to taste.
- Place in a gratin dish, spread the rest of the cheese and bake in the oven for about 15 minutes until golden-yellow.