Step 1

Heat the oil and butter in a large saucepan or Dutch oven. Add the onions and cover the pot to sweat the onions. Cook for about 8 minutes until softened. Shake the pot every two minutes to prevent the onions sticking.

Step 2

Add the flour to the onions in the pot and stir over medium heat for 2 minutes.

Step 3

Add the stock gradually, mixing to combine fully with each addition.  Add the diced potatoes and cook over a low heat for 30 minutes.

Step 4

Serve in warmed bowls with crusty buttered bread rolls or cheese toasties.