Mayonnaise

Whisk an egg yolk with a teaspoon of mustard and a little lemon juice or vinegar. Add neutral oil drop by drop at first, whisking constantly; once it thickens, pour the oil in a thin steady stream and season.

Put a teaspoon of warm water in a clean bowl and whisk the split mayonnaise into it a little at a time. If that does not bring it together, start with a fresh egg yolk and slowly whisk in the split mixture.

Use pasteurised egg, keep the mayonnaise covered in the fridge and use it within 24 hours. Don’t leave it at room temperature for more than two hours.

Yes. Spread a thin layer on the outside of bread for a crisp, golden toastie, or brush it over chicken before baking to help breadcrumbs stick. Keep the chicken cooking until its centre reaches 75 °C.

It is a classic dressing for coleslaw and potato salad, and works well in egg, tuna and prawn sandwiches. Stir it with chopped gherkins and capers for tartare sauce, or with garlic and lemon for a quick dip.

In the foods compared, light mayonnaise has 296 kcal per 100 g, against 327 kcal in mayonnaise. The name alone does not tell you how a particular recipe will compare.

Yes: use it in the same amount for sandwiches, coleslaw, dips and potato salad. It is made without egg, so it is a useful choice for egg-free cooking.