Brain food: Make my frozen berries like the supermarket's, please

How do I freeze my home-grown berries so they are like the ones you can get from the supermarket? Mine are mushy. M. Carvosso

You need an IQF, or Individually Quick Frozen machine. Or should I say plant? They start at about $1.5 million and need half a hectare of land but will let you process about 35 tonnes of berries a day. It's expensive technology that washes, sorts, grades and then rapidly freezes individual berries, pea, beans, corn kernels etc in a constant stream of super-chilled air. The fruit or vege freeze incredibly quickly. When you freeze a tub of strawberries at home, they freeze slowly and large ice crystals form, rupturing the cell walls, allowing the liquid inside to leak out. The best you can do at home is wash and prepare the fruit and spread out on a thin tray (a thick one will retain heat and slow freezing). The cold air will freeze them faster than if they were in a tub. When frozen, place the berries in a container and leave in the freezer until needed. They won't be as "perfect" as a commercial berry but will be significantly less mushy.

I am making traditional stuffing for the turkey this Christmas but one guest is allergic to onions. M. Brewer

Take out the onions and it's no longer traditional stuffing. It's 21st-century stuffing for a world with stuffed-up digestion because we've all been eating crap factory food. Is it too early to say "Merry Christmas"? Or should that be "Happy Holidays"? Two options: make a separate onion-free stuffing and bake it in a covered muffin tray. Or make a really good onion-free stuffing that everyone can enjoy. You need to replace the sugar (onions are about 4.7 per cent fructose) and the umami (onions are quite high in glutamic acid). First, saute some finely diced carrot and celery, a cup of each, in some butter. Season with salt as you cook to draw out the moisture. Carrots are sweet and the celery will help with the umami. Cook very slowly until very soft. Add to the stuffing. You could increase the glutamic acid with tomato paste but that would render the stuffing pink. Instead, add several tablespoons of finely grated parmesan cheese. That will add salt, acid and umami but you shouldn't taste it too much over the fresh herbs. That onion tang? Some would suggest adding asafoetida but it is just a little too bitter and heading too far east in a culinary sense. A drop or two of truffle oil (even though I hate the stuff) will add a sulphurous note without being discordant.

When making pastry can I rest it in the fridge overnight? C. French

Yes. It will be even better. If you need to you can make pastry, form it into a thick sheet half the size of A4 and freeze it. Defrost it and roll it out. Great if you want to make several batches at the one time.

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