2 small carrots, trimmed, scrubbed and halved lengthways
3 garlic cloves, crushed or finely chopped
1 large onion with skin left on, thickly sliced
2 rosemary sprigs, needles picked and finely chopped (or 2 tsp dried)
fresh rosemary or thyme sprigs, to garnish (optional)
mint sauce, to serve
2 tbsp redcurrant jelly, plus extra to serve
salt and freshly ground black pepper
2–4 tbsp cornflour (or gravy granules, see tip)
2 tsp olive oil
1 lamb shoulder (about 1.5kg/3lb 5oz), boned and rolled
600ml/20fl oz hot lamb stock (made with a stock pot if possible)