900g/2lb butternut squash, peeled, seeds removed and cut into 1cm/Β½in cubes
1 lime, juice only
200g/7oz onion, finely sliced
salt and freshly ground black pepper
2 tbsp olive oil
2 vegetable stock cubes
50²µ/1ΒΎ΄Η³ϊ butter
750ml/1ΒΌ pint milk