Cheese & spinach penne with walnut crumble

• penne↗500g g
• leeks↗2

  sliced

• butter↗85g g
• plain flour↗85g g
• ready-made English mustard↗2 tsp tsp
• nutmeg↗
• milk↗1l l

  plus a bit extra

• mature cheddar↗350g g

  grated

• French bread↗4

  diced

• walnut↗85g g
• spinach↗400g g

Step-by-step instructions

1. 1

   If you are eating one of the pasta bakes now, heat oven to 190C/170C fan/ gas 5. Boil the pasta with the leeks for 10 mins, then drain.

2. 2

   Meanwhile, put the butter, flour, mustard, nutmeg and milk in a large pan with some seasoning. Gently heat, stirring all the time, until bubbling and thickened, then cook for 2 mins more, stirring frequently. Remove from the heat and stir in two-thirds of the cheese. Toss the remaining cheese with the bread and walnuts.

3. 3

   Cook the spinach in the microwave, or pour a kettle of boiling water over it to wilt, then squeeze out the excess water. Stir into the sauce with the pasta, leeks and some seasoning. If necessary, add a little extra milk to loosen. Divide between 2 ovenproof dishes and scatter the bread mixture on top. If eating straight away, bake for 40 mins until golden, or cool to freeze.