Heat oven to 200C/180C fan/gas 6. Pour a good glug of oil in a large roasting tin and put in the oven. Put the potatoes in a saucepan and cover with boiling water from the kettle. Bring to the boil and cook for 7-8 mins.

Drain the potatoes, then toss them in the polenta to help them dry out and get a fluffy coating. Carefully tip the potatoes into the hot roasting tin, drizzle over a little more oil and toss to coat.

Roast for 30 mins, then turn them over and roast for 30 mins. Turn once more and cook for a further 10 mins. These can go on the lower shelf while you make an accompanying dish (such as our veggie toad-in-the-hole), and can cook for a further 15-20 mins if required.