Thick, golden mayonnaise made at home is a world away from the shop-bought version and perfect with salads or shellfish. It's made by whisking egg yolks and oil, so the oil droplets are held by the egg in a stable emulsion. A little lemon juice cuts the richness. Use one yolk for every 100ml oil and avoid very strong-flavoured oils. Try a light olive oil, or blend virgin oil with sunflower. This recipe is for aïoli, which is just mayonnaise with a shot of garlic (I've added herbs, too). But you can also use this recipe to make plain mayonnaise: just leave out the garlic and herbs.
Crush the garlic and a pinch of salt to a smooth paste in a pestle. Transfer to a basin. Add the egg yolks, lemon juice and seasoning and whisk together.
Add about 2 tsp oil and whisk vigorously to incorporate. Continue to add the oil slowly in a thin stream, whisking constantly, so the oil is emulsified. It's helpful to have someone else pour while you whisk, but it's perfectly possible to do this on your own, adding a little oil at a time. Alternatively, use a blender, drizzling the oil through the lid as the blender works. Either way, keep whisking until all the oil has been incorporated and you have a smooth, wobbly mass. Stir in the herbs, tip into a serving bowl and garnish.
Occasionally mayonnaise can 'split' or separate into a lumpy mess of egg and oil during the whisking. To avoid this, ensure that the ingredients are at room temperature, and add a starchy, stabilising ingredient, such as 2 tsp mustard, before you begin adding the oil. If the mixture does split, put a fresh yolk in a clean bowl and whisk in 1 tbsp just-boiled water. Gradually whisk in the split mixture until you have re-established the emulsion.
Homemade mayonnaise should be kept chilled and eaten within 24 hours. As it contains uncooked egg, it's not suitable for pregnant women, young children, the elderly or infirm.