2 medium carrots, roughly chopped
2 celery stalks, roughly chopped
1 onion, thinly sliced
1 rosemary sprig
2–3 sage leaves
250g/9oz easy-cook polenta
8 tbsp olive oil
3 tbsp tomato purée
knob of butter
25g/1oz parmesan
6 chicken breasts, or chicken thighs, bones removed
500ml/17 fl oz chicken stock
175ml/6fl oz white wine