Georgina Hayden's Quick and Easy Recipe for Leek and Comté Croques

While I love a classic croque monsieur, I sometimes prefer to mix things up by incorporating various cheeses and adding other flavorings – I basically live life on the edge. This version with leeks feels cozy and seasonal, and a bit special, too. If I have guests visiting, I'll prepare the leek and sauce mixture in advance, then fill the sandwiches just before baking and serve them with a bitter leaf salad.

Leek and Comté Croques

Prep 10 minutes
Cook 40 minutes
Serves 4

Two leeks (approximately 300 grams), trimmed and finely sliced
Two garlic cloves, skinned and thinly sliced
60g unsalted butter, plus extra for buttering
Salt and pepper
60g plain flour
300ml whole milk
1 heaped tsp English mustard
100g comté, grated finely
60g mature cheddar, grated finely
Eight slices of bread

Place the cut leeks, butter and garlic in a medium pot on a medium-low heat, season well, then saute, stirring occasionally, for 15 to 20 minutes, until the leeks have softened and become caramelized.

Meanwhile, heat the oven to 240C (220C fan)/475F/gas 9. Mix in the flour into the leek mix and cook for about a minute, until it becomes a biscuity roux. Add the milk, turn up the heat a little and whisk until the sauce is smooth. Keep whisking for a minute, until the sauce thickens, then take off the heat. Stir in the mustard and two-thirds of the grated comté and cheddar, and put to one side.

Brown the bread slices (in batches, if need be), then spread butter on one side of each slice. Lay four slices of toast butter-side down on a parchment-covered tray. Spread each one with a generous amount of the leek sauce, then top with a another bread slice, this time butter-side up. Finish each sandwich with a layer of the remaining leek bechamel, then top with the remaining grated cheese. Cook in the oven for 10 to 14 minutes, until the croques are browned, bubbling and oozy.

Serve straight away, with a dressed salad on the side, if you like.