Ingredients ·25g (1oz) butter, softened ·1 red onion, thinly sliced ·4 plums, pitted and sliced ·25g (1oz) sultanas or raisins ·25g (1oz) dark or light muscovado sugar ·1/2 teaspoon finely grated fresh root ginger or a pinch of powdered ginger ·salt and freshly ground black pepper ·150g (5oz) Caerphilly cheese, crumbled or grated ·2 teaspoons wholegrain mustard or a pinch of dry mustard ·a few drops of Worcestershire sauce ·4 thick slices rosemary foccacia bread or crusty white bread
1. First of all, make the relish. Melt half the butter in a small saucepan and add the onion. Cook gently until softened and well-browned - about 10 minutes. Add the plums and sultanas or raisins, sugar and ginger and 150ml (1/4 pint) hot water. Simmer until the plums are very soft and pulpy, and most of the liquid has evaporated. Taste and season with a little salt and black pepper. 2. To make the rarebits, work the remaining butter and cheese together, mixing in the mustard and Worcestershire sauce to make a stiff paste. 3. Toast one side of the foccacia or crusty bread, then spread the untoasted side with the cheese mixture. Grill until melted and bubbling. Serve, topped with the warm plum relish.