Freezer-friendly lasagne

1 Finely slice the leek, wash and drain well.

2 Heat oil in a large pan over a medium heat. Add leek and cook for 15 minutes, stirring often.

3 Add flour, nutmeg and pepper and stir well to coat. Gradually add milk, stirring continuously. Bring to the boil, then reduce heat to low and cook for 5 minutes or until thickened, stirring regularly.

4 Pour white sauce into a food processor and blitz until smooth.

5 To build lasagne, spoon a quarter of the bolognaise sauce into a deep ovenproof dish (around 20cm x 30cm) and spread out evenly. Spoon over a quarter of the white sauce, then lay over some lasagne sheets — enough to cover the sauce in a single layer. Repeat this three times, finishing with a layer of white sauce. Allow to cool, then sprinkle over the cheese.

5 Bake for 40 minutes, or wrap the dish in plastic wrap then tin foil and place in freezer, clearly marked with a name and date.