Add the diced onion, minced garlic, drained chickpeas, crushed tomatoes, harissa paste, vegetable broth, cumin, smoked paprika, salt, pepper, and olive oil to your slow cooker insert. Give everything a good stir so the harissa paste is evenly distributed and not sitting in one spot.

Place the lid on the slow cooker and cook on low for 6 hours or on high for 3 hours. The chickpeas will soften slightly and absorb the spiced broth, and the onion will essentially disappear into the stew.

About 15 minutes before you are ready to eat, lift the lid and taste the stew. This is your moment to stir in an extra tablespoon of harissa if you want more heat, or add a pinch more salt if it needs it.

Add all of the baby spinach to the pot. It will look like a lot but it wilts down quickly. Stir it into the hot stew, replace the lid, and let it cook for another 10 to 15 minutes until the spinach is fully wilted and tender.

Squeeze the juice of one lemon over the stew and stir it in. This brightens the whole dish and balances the smoky heat from the harissa. Taste one more time and adjust salt or lemon as needed.

Spoon the stew into bowls over cooked couscous, or serve it alongside warm flatbread for scooping. A drizzle of olive oil on top is a simple but worthwhile finish.