Heat oil in a deep skillet over medium heat until shimmering. Add the diced onion and cook, stirring occasionally, until soft and golden, about 5 minutes.
Add the minced garlic and cook for about 30 seconds until fragrant, being careful not to burn it.
Sprinkle in the toasted cumin, turmeric, and coriander, stirring constantly for 1-2 minutes until the spices release a warm aroma and coat the onion mixture evenly.
Add the tomato paste and cook, stirring frequently, for about 8 minutes until the mixture darkens slightly and becomes fragrant.
Stir in the drained chickpeas and pour in the coconut milk, stirring to combine. Bring the mixture to a gentle simmer and cook uncovered for 10 minutes, allowing the flavors to meld and the sauce to thicken slightly.
Add the thawed and drained spinach, stirring until wilted and evenly distributed, about 3-4 minutes. The spinach should turn bright green and soften.
Season with salt and pepper to taste. Squeeze in fresh lemon or lime juice to brighten the flavors. Adjust seasoning as needed.
Remove from heat and let sit for a couple of minutes to allow flavors to settle. Serve hot over rice or with crusty bread, garnished with extra lemon if desired.
