675²µ/1Β½±τ²ϊ Jerusalem artichokes, peeled, halved and sliced
1 large onion, halved and sliced
2 tbsp roughly chopped parsley
4 sprigs fresh thyme
1 bay leaf
salt and freshly ground black pepper
2 tbsp extra virgin olive oil
1 litre/1ΒΎ pints hot chicken or vegetable stock
2 tbsp white wine vinegar
150g/5oz single Gloucester, mature cheddar or gruyère cheese, coarsely grated (optional)
6 thick slices baguette (optional)