Nibblous | chestnut and chorizo soup (sopa de castanos)

Ingredients

• 4 tbsp olive oil
• 1 large spanish onion, diced
• 1 medium carrot, diced
• 1 celery stick, thinly sliced
• 120g mild cooking chorizon, cut into 1cm cubes
• 2 garlic cloves, thinly sliced
• 1 tsps ground cumin
• 1 1/2 tsps chopped thyme leaves
• 2 small dried red chillies, crushed
• 2 tomatoes, roughly chopped
• 500g cooked peeled chestnuts, roughly chopped
• 20 saffron threads, infused in 3-4 tbsps boiling water
• 1 litre water
• salt and black pepper