JULIE BIUSO

In season: rhubarb.

America may have its gardening cornerstone trio of companion planting known as the Three Sisters (corn, beans and squash) but I think we can lay claim to a backyard garden trio of our own in New Zealand: a lemon tree, a silverbeet patch and a rhubarb plant. A rhubarb plant is not so common now because it requires space, it’s slow to provide a good yield – it’s best not to pick it for the first year so that the plant can establish itself – and not everyone understands how to cook it well.

Even before you get to cooking, it’s important to note that rhubarb reacts with aluminium and carbon steel. When cut with a carbon steel knife – carbon steel was favoured over stainless steel in knife-making because it kept a sharper edge – the knife will blacken and darken the rhubarb and chopping board and make everything smell and taste metallic. Aluminium pots were popular when I grew up but if you cook rhubarb in aluminium the result is a grey-green unappealing mess. Advancements in knife-making have seen household carbon steel knives become a thing of the past and, likewise, aluminium pots and pans have dropped in popularity because of suspected (but inconclusive) links to Alzheimer’s disease.

Rhubarb can be the most elegant of fruits. Cut into neat short lengths, cooked gently until just about tender with its pretty pink syrup pooled around, it has plenty of appeal, but it can be a beast if cooked into long shreds of mush that get tangled around your teeth. The point between rhubarb holding its shape and rhubarb that has passed that point and blown apart into a purée (it swells and bursts) is a matter of 1-2 minutes’ cooking time. Once cooking momentum starts, you’ve got to keep an eye on it, checking every minute or so. It’s not tricky, but don’t nod off on the job!

To prepare, cut the stalks into short lengths, about 2-3cm long, lay in a shallow dish –

I like using Pyrex or glass so I can see what is happening through the side of the dish – then sweeten with brown or white sugar (redcurrant jelly and orange juice is another option). A good ratio is 50 grams caster sugar to 600 grams rhubarb. Cover the dish and bake for about 15 minutes in an oven preheated to 190°C. Then start checking every minute until it is 90 per cent tender. Remove the dish from the oven; it will finish cooking with residual heat.

You can use tinfoil to cover the rhubarb as long as the foil doesn’t touch it (if it does come in contact, the rhubarb may develop a metallic taste). Or cover the dish with baking paper first, then to lay foil over the top that you can tuck in to keep the baking paper in place. This baking paper and foil combo is a handy tip when cooking turkey, ham or chicken; the paper prevents the foil sticking to the food and pulling off lovely browned or glazed morsels.

I’ve referred to rhubarb as a fruit, though technically it is a vegetable. I’ve enjoyed avant-garde savoury dishes starring rhubarb in Spain, and think rhubarb is a great addition to relish and chutney, but my preference is for sweetened rhubarb served with a silky custard, or layered with rich cream and puff pastry in millefeuille, or in a classic pie with apple and ginger or, perhaps best of all, in a crumble. Gently cooked as described, rhubarb is also gorgeous on top of cheesecakes and meringues and can be added to cakes, batters and muffins, adding a zingy, fruity taste.

Rhubarb is available all year round, though the stems are fatter and redder in winter and somewhat sweeter. When removing rhubarb from the plant, twist the stalk at the base and pull it off, rather than cutting with a knife, as it will keep fresher. Trim away the leaves as soon as you pick it as they draw moisture from the stalks. The leaves are toxic but they break down satisfactorily in a compost bin. The stalks have plenty of fibre along with potassium and a good dose of vitamin C but, like sorrel and spinach, rhubarb contains oxalic acid, which hinders the body’s absorption of rhubarb’s plentiful supply of calcium and iron, and it can increase the occurrence of kidney stones in certain people.

If you are buying rhubarb, look for stalks that have been pulled from the plant, not cut, as they’ll keep fresh for longer. Avoid spongy or withered stalks. Wash and dry and put them in a plastic bag and refrigerate until required. Freshly picked rhubarb will keep for about two weeks. It can also be frozen. Cut it into short lengths, lay the pieces on a tray and freeze, then tumble into a sealable bag or container and return to the freezer.