Step 1

Preheat oven to 220°C/200°C fan-forced.

Step 2

Cook pasta in a large saucepan of boiling salted water, following packet directions, until tender, adding peas, beans and asparagus in the last 4 minutes of cooking time (see note). Drain, reserving 1/2 cup cooking liquid. Return pasta mixture to pan.

Step 3

Meanwhile, blend cornflour and 1/2 cup milk together in a jug. Place remaining milk in a saucepan. Bring to the boil. Whisk in cornflour mixture. Bring to the boil. Cook, stirring, for 1 minute, or until sauce thickens. Stir in half the cheese.

Step 4

Add tuna and white sauce to pasta mixture. Stir to combine. Season with salt and pepper. Spoon into a greased 8-cup capacity baking dish. Sprinkle with remaining cheese. Bake for 20 minutes or until golden. Serve.