Step 1

Put the prepared potato chunks into a large saucepan with enough salted water to take the pasta later, and bring to the boil.

Step 2

Cook the potatoes until tender, about 20 minutes, then add the pasta. Check the packet cooking instructions, and at about 4 minutes before the end of the specified cooking time, add the green beans. If you are using artisanal egg linguine, which takes less time, you will need to alter your strategy.

Step 3

While this is bubbling away, whiz the ingredients for the pesto in a food processor. Before you drain the saucepan, remove and reserve about ½ cupful of the cooking liquid. Tip the drained potatoes, beans and pasta back into the dry pan.

Step 4

Add the pesto from the processor and enough cooking water to give a runny sauce that coats the strands of pasta as you work it through with a fork or pasta claw. Serve immediately.