Harissa is a chili pepper paste that's deeply savory, slightly acidic, and a little sweet. It's most common in Northern Africa - I tasted it first in Morocco, where it is popular to add into couscous. You can purchase harissa in mild or hot - mild has just a touch of heat. The creamy harissa chickpeas and spinach part of this recipe were inspired by Shilpa Uskokovic. I've simplified the process a bit and combined some elements, but the sweet / spicy / pickley magic came straight out of her brain!