By Nigella Lawson
Most butchers can get you tail bits of fillet which will cost less and which you won’t mind so much tearing into raggedy scraps. Cook a buttery mound of basmati rice to eat with.
Put 30 g of butter in a frying pan with a drop of oil. Put on the heat, add the onion and fry gently, stirring frequently, until soft and beginning to colour. Add 30 g more butter and when melted toss