Cook the rice according to package directions.
In a large pot, heat 2 tbsp. oil over medium-high. Add the lamb and season with salt and pepper. Cook, breaking up the lamb with a spoon, until browned, about 5 minutes. Transfer to a plate.
In the pot, heat the remaining 1 tbsp. oil over medium. Cook the onion, garlic, spices and harissa, stirring, until onion is tender, 8 minutes; season. Add the tomatoes and stock and cook over medium-high until the sauce thickens, 10 minutes.
Off heat, stir in the lamb, chickpeas and spinach until spinach wilts; season. Serve rice topped with the stew.