Asparagus, mint & lemon risotto

INGREDIENTS

• 1 litre organic vegetable or chicken stock
• 2 tablespoons olive oil
• 1 large onion, peeled and finely chopped
• 4-5 sticks celery, trimmed and finely chopped
• 600 g risotto rice
• 250 ml vermouth or dry white wine
• 2 bunches asparagus, woody ends removed and discarded
• 700 ml organic vegetable or chicken stock
• 50 g butter
• 1 small handful Parmesan cheese, freshly grated, plus a block for grating
• 1 bunch fresh mint, leaves picked and finely chopped
• zest and juice of 2 lemons
• sea salt
• freshly ground black pepper
• extra virgin olive oil