Heat oil in a large pot over medium heat. Add garlic, onion and ginger. Season with salt and pepper and cook, stirring occasionally until onion is translucent and starts to brown a little around the edges, 3 to 5 minutes.
Add turmeric, red-pepper flakes and chickpeas, and season with salt and pepper. Cook, stirring frequently, so the chickpeas sizzle and fry a bit in the spices and oil, until they’ve started to break down and get a little browned and crisp, 8 to 10 minutes.
Using a wooden spoon or spatula, further crush the remaining chickpeas slightly to release their starchy insides (this will help thicken the stew). Add coconut milk and stock to the pot, and season with salt and pepper. Bring to a simmer, scraping up any bits that have formed on the bottom of the pot. Cook, stirring occasionally, until stew has thickened and flavors have started to come together, 30 to 35 minutes. (Taste a chickpea or two, not just the liquid, to make sure they have simmered long enough to taste as delicious as possible.) If after 30 to 35 minutes you want the stew a bit thicker, keep simmering until you've reached your desired consistency.
Add greens (I use spinach) and stir, making sure they’re submerged in the liquid. Cook a few minutes so they wilt and soften, 3 to 7 minutes, depending on what you’re using. (Swiss chard and spinach will wilt and soften much faster than kale or collard greens.) Season again with salt and pepper.