Blend all ingredients in a high speed food processor until the mixture becomes a chunky ‘mince’. Set aside.
Pulse all the ingredients together in a food processor until roughly chopped. Transfer into a bowl.
Wash the cos lettuce leaves and serve with salsa, avocado slices and walnut mince.
Notes: You can substitute sunflower seeds for the walnuts in this recipe if you have a nut allergy. If you have any leftovers store them in an airtight container for lunch the next day!