This is a handy mixture that can be used as a spread, a dip or a sauce, or put it in a piping bag and squiggle it over tortillas and tacos.
1 large perfectly ripe avocado
1 tsp lime juice
Pinch of salt
½ cup plain unsweetened yoghurt
Halve avocado, remove stone, then flesh. Put flesh in the bowl of a mini food processor, or in a blender, with lime juice and salt. Whiz to break up avocado. Add yoghurt and whiz until perfectly smooth. Transfer to a bowl and keep covered and refrigerated until ready to use (the crema will keep up to a day).