Leek, Chard & Tarragon Soup with Wild Garlic Pesto

Ingredients

• 1 tbsp olive oil
• 1 1/2 tbsp butter
• 2 leeks, thinly sliced
• 1 1/2 litres well-flavoured chicken stock
• A large pinch of saffron, soaked in 2 tbsp hot water
• 1 strip of lemon zest
• A small bunch of tarragon, stems and leaves separated
• A small bunch of baby chard leaves
• 3 small courgettes, sliced into rounds
• 75g baby broad beans, blanched and skinned
• 50g fresh peas
• 200g cooked chicken (optional)
• 100g wild garlic (a mixture of leaves, stems and buds)
• 50g Cornish Yarg, crumbled
• 50g blanched hazelnuts or cobnuts, lightly toasted
• Zest and juice of 1/2 lemon
• Olive oil
• A few small leaves of wild garlic
• A few wild garlic flowers (optional)
• Black tahini paste (optional)