Lamb and kidney suet pudding with rosemary

Name: Lamb and kidney suet pudding with rosemary
Ingredients: 30g/1oz unsalted butter; vegetable oil, for frying; 2 banana shallots, sliced; 2 garlic cloves, sliced; 1 tbsp plain flour; 1 tbsp finely chopped fresh rosemary; 500g/1lb 2oz lamb shoulder, trimmed and cut into bite-size pieces; 3 lambs’ kidneys, halved, tough white core removed, cut into bite-size pieces; 150ml/5fl oz red wine; 150ml/5fl oz rich beef stock; salt and freshly ground black pepper; butter, for greasing; 285g/10oz self-raising flour; 125g/4½oz suet; 1 tsp baking powder