Green goddess dressing

Ingredients

• 1 ripe avocado
• 1/2 cup fresh coriander leaves
• 1/4 cup parsley leaves
• 1/4 cup fresh lime juice
• 1/2 cup water, plus more if required
• 1/4 cup olive oil
• 1/4 cup raw walnuts or cashews
• 1 clove garlic, crushed
• 1/4 tsp sea salt
• 1/4 tsp black pepper