Ask Nigel

Q How do I cook French beans so they don't squeak when I eat them?
Julia, Derbyshire

A Julia, you need to oil them. Cook them in merrily boiling water till they are tender and have a slight bend to them, then toss in olive oil and a squeeze of lemon. No squeaks. Personally, I rather like my beans squeaky.

Q How important is it to skim the scum off stock? I always end up spending ages obsessively removing the grey bubbles with a spoon, but I'm not sure it makes much difference apart from making the liquid clearer. Also do you need to do it with lentils and beans?
John Mead

A John, I really do think you need to do it. The reason is that if the froth is allowed to boil into the stock it will make it cloudy. It is one of those jobs that you need to do thoroughly. I don't think it matters with lentils, however. I do it only because I hate the look of it bobbing up and down on top of the water.

Q I like the idea of frying up leftover mash for breakfast as you suggest, but my refried mash just seems to 'melt' and stick to the pan rather than forming a crust. Maybe it is too buttery?
John Mead

A John, two questions in one week. I'm not sure that's allowed. But yes, you are right, a bit too much butter in the mash will make it difficult to fry. I sometimes do it in a non-stick pan with no extra butter. The fry-up is still on the soft side, but it does form a neatish cake if you keep pulling the edges in with a spatula as they cook.

· If you have a cooking question for Nigel, email ask.nigel@observer.co.uk

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