Heat a skillet over medium heat and add olive oil. Once shimmering, add chopped onion and cook until translucent and fragrant, about 4 minutes, stirring occasionally.
Add minced garlic, cumin, smoked paprika, and chili powder to the skillet. Cook for another minute until spices are fragrant, filling the kitchen with warm aromas.
Transfer the sautéed aromatics to your slow cooker. Pour in the drained chickpeas, diced tomatoes, and vegetable broth. Stir well to combine all the ingredients evenly.
Cover the slow cooker and cook on low for 6 to 8 hours. The stew will thicken and develop a rich, fragrant aroma as it bubbles gently throughout the day.
About 30 minutes before serving, stir in chopped greens. Cover and let them wilt in the warm stew, turning vibrant and tender.
Once greens are wilted, open the lid and squeeze in fresh lemon juice. Stir well, taste, and adjust seasoning if needed.
Serve the stew hot, with a drizzle of olive oil on top if desired. Enjoy the thick, comforting texture and vibrant flavors with crusty bread or rice.