Prepared onions are a boon to any cook. It’s also worth freezing shallots or pickling onions ready for later use.

Choose firm onions, whatever their size, with stiff, papery skins. Any that appear damp or are rotting or sprouting are not worth freezing.

Peel, leave baby (pearl) onions whole, and slice or chop larger ones. Blanch in boiling water – 1 minute for chopped onions, 2 for sliced, 3 for whole ones. Drain and plunge immediately in a bowl of iced water to cool. Drain again and dry on kitchen paper.

Pack in convenient quantities in polythene bags or rigid containers. Remove the air, seal, label and freeze. Storage time: 6 months.