Butternut squash soup with parsley purée

Name: Butternut squash soup with parsley purée
Ingredients: 1.8kg/4lb wedges of butternut squash; 3 tbsp olive oil; 6 cloves garlic, 4 whole, unpeeled and 2 finely chopped; 2 sprigs of thyme; Salt and freshly ground black pepper; 2 onions, finely chopped; 2 carrots, finely sliced; 2 sticks celery, finely sliced; 1 tbsp freshly chopped sage; 2 litres/3½ pints hot vegetable stock; 1 bunch flatleaf parsley, roughly chopped; 1 clove garlic, crushed; 30g/1oz parmesan, finely grated; 100ml/3½fl oz extra virgin olive oil; Lemon juice, to taste