1.
Preheat the oven to 220°C (425°F, gas mark 7). Put the squash
and red onions in a large roasting tin and scatter over the sliced garlic.
Drizzle with the oil and season with salt and pepper to taste. Toss to coat the
vegetables with the oil, then place the tin in the oven and roast for 15
minutes.
2.
Remove the tin from the oven and add the leeks and asparagus.
Toss gently to mix with the other vegetables, then return to the oven. Roast for
a further 20 minutes or until all the vegetables are tender and beginning to
brown.
3.
Meanwhile, cook the pasta in a large saucepan of boiling water
for 10–12 minutes, or according to the packet instructions, until al dente.
4.
While
the pasta is cooking, make the sauce. Measure 4 tbsp of the cold milk into a
jug, add the cornflour and stir to make a smooth paste. Heat the remaining milk
in a saucepan until almost boiling. Stir the hot milk into the cornflour
mixture, then return to the saucepan and heat gently, stirring, until the
mixture boils and thickens. Simmer for 2 minutes.
5.
Remove the sauce from the heat and add about two-thirds of the
cheese and the mustard. Season with salt and pepper to taste.
6.
Take
the tin of roasted vegetables from the oven. Drain the pasta well in a colander,
then tip on top of the vegetables and stir to combine. Stir in the sauce.
Sprinkle the remaining cheese evenly over the top. Return to the oven and bake
for 10–15 minutes or until golden and bubbling. Serve hot.
