Stir in the harissa paste and let it cook for a minute, then add the sweet potatoes, chickpeas, crushed tomatoes, and vegetable stock to the pot.
3 tablespoons harissa paste
½ lb sweet potatoes
2 cans (14 oz / 400 g) chickpeas
2 cans (14 oz / 400 g) crushed tomatoes
1 cup vegetable stock