Roast pork with apples, cider vinegar & rosemary

INGREDIENTS

• 2-2.25kg/4lb 8oz-5lb loin of pork on the bone, rind removed
• 1 garlic clove , crushed
• 1 tsp finely chopped fresh rosemary , plus a few extra whole sprigs
• 1 large onion , thickly sliced
• 2 tbsp cider vinegar , plus extra for gravy
• 2 tbsp redcurrant jelly, plus extra for gravy
• 500ml vegetable stock
• 50g butter
• 1 small onion , finely chopped
• 1 small lemon , grated zest
• 50g fresh white breadcrumbs
• 1 tsp finely chopped fresh rosemary needles
• 6 good-sized apples , preferably Golden Delicious