Fish stock

Ingredients

• 1.25kg white fish bones (ask the fishmonger)
• Groundnut or grapeseed oil
• 150g peeled and finely sliced onion (approx. 2 medium onions)
• 75g peeled and finely sliced carrot (approx. 1 large carrot)
• 75g finely sliced celery (approx. 2–3 sticks of celery)
• 100g finely sliced fennel
• 100g finely sliced button mushrooms
• 1 clove of garlic, peeled and finely sliced
• 150g sliced ripe tomatoes (approx. 2 medium tomatoes)
• 180g dry white wine
• 75g dry white vermouth
• 500g mussels, cleaned
• ¼ tsp saffron strands
• ½ tsp fennel seeds
• 50g flat-leaf parsley (stalks and leaves)
• 2 sprigs of thyme
• 12 basil leaves
• 6 tarragon leaves
• 4 strips of lemon zest, removed with a peeler