Toast walnuts in the oven for 5-7 minutes, until lightly browned and fragrant. Remove from the oven and set aside to cool.
Put all ingredients into a food processor and whizz to combine, stopping to scrape down the sides as needed. The dip should still have some texture - you don't want it to be perfectly smooth.
Taste and adjust seasoning as necessary. Add more chilli flakes or lemon juice, if you like.
Notes
Chargrill and skin your own red capsicum (peppers) or use the kind that come in a jar.
If you don't have pomegranate molasses, replace with 1-2 teaspoon of red wine vinegar and 1 teaspoon of sugar.