Rump of lamb, kidneys, shallot purée & broad beans

Ingredients

• 1 tbsp olive oil -
• 6 trimmed lamb rumps, each about 200g/8oz (see tip) -
• small knob of butter -
• 6 lamb kidneys, split lenthways through the middle, white core removed -
• 600g cooked and double podded broad bean -
• 1 tbsp white wine vinegar -
• 3 tbsp olive oil -
• 1 small garlic clove , finely chopped -
• 1 tbsp finely chopped flat-leaf parsley -
• 85g unsalted butter -
• 800g shallots , roughly chopped -
• 1 bay leaf -
• 150ml double cream -