Step 1

For quickled onions, toss onion, salt and sugar in a bowl. Set aside for 15 minutes to pickle slightly. Stir through vinegar. Set aside for at least 2 minutes or until needed.

Step 2

Clean and trim the leek. Place in a microwave-safe container and microwave uncovered on high for 4 minutes or until the leek is just tender. Split lengthwise then remove the soft inner layers and place in a bowl, discarding the outer layers. Stir through garlic and cheeses.

Step 3

Preheat a sandwich press or frypan over medium heat. Butter one side of each slice of bread. Place, butter-side down, on a piece of baking paper.

Step 4

Spread Dijon over one slice. Make a slight indent in the centre of the other slice of bread and fill with leek mixture. Season, then top with the Dijon-spread slice of bread. Cook for 2 minutes each side or until golden and cheese is melted (if using a sandwich press, don’t push down too hard).

Step 5

Serve toastie with quickled onions.