When they are ripe and sweet, buy a big batch of cherry tomatoes, to make double or triple the quantity of sauce. It takes a while to cook – just over an hour – but it keeps in the fridge for 5 days and freezes for up to a month. The ancho chilli adds a lovely smoky richness, but can be replaced by ¼ tsp sweet smoked paprika if you have this to hand rather than ancho. Alternatively, if you don’t want the kick, leave the chilli out altogether.