Green Pea, Harissa and Coriander Hummus

1½ cups frozen peas, blanched
½ avocado
¾ cup cannellini beans (½ of a 400 gram tin)
2 tablespoons tahini
1 teaspoon harissa or more to taste
zest and juice 1 lime
2 cloves garlic, crushed
¼ cup packed coriander 
2 tablespoons olive oil
1 tablespoon water
sea salt and ground pepper
To serve
¼ cup tamari roasted almonds, chopped
2 tablespoons chopped coriander