John Whaite served up a tasty vegetarian mushroom and artichoke lasagne on Steph’s Packed Lunch.

The ingredients are: 3 tablespoons olive oil , 1 small onion, finely chopped , 500g chestnut mushrooms, very finely chopped (I use a food processor) and 500g fresh lasagne sheets.

For the sauce: 125g unsalted butter, plus extra for greasing , 125g plain flour , 1 litre milk , 500ml vegetable stock , 200g (drained weight) artichoke hearts from a jar, finely chopped, 1½ teaspoons finely chopped rosemary , 1½ teaspoons freshly grated nutmeg , 1½ teaspoons sea salt flakes (or ½ teaspoon table salt) , 1½ teaspoons coarse black pepper (or ½ teaspoon fine) , 350g Gruyère cheese, plus a little extra for the top, finely grated and 2 tablespoons vodka (or white wine).

See recipes by John in his book titled:A Flash in the Pan: Simple, speedy stovetop recipes available from Amazon now.