Cut the chicken thighs into 1-inch chunks and set aside. Peel and dice the sweet potato into 1/2-inch cubes, then finely dice the shallots and mince the garlic. Having everything prepped and ready will make the next step quick and seamless. I find that dicing the sweet potato smaller helps it cook evenly with the chicken in the time allotted.
Add the cubed chicken, diced sweet potato, shallots, and minced garlic to your slow cooker. Pour in the full-fat coconut milk and chicken stock, then add the fish sauce, turmeric, grated ginger, and cayenne. Stir everything together until well combined, making sure the spices are evenly distributed throughout the liquid. This layering of aromatics and spices at the start ensures they'll infuse the entire dish.
Cover the slow cooker and cook on high for 3-4 hours or on low for 6-8 hours, depending on your schedule. The chicken should be very tender and easily shred with a fork, and the sweet potato should be soft but still hold its shape. I prefer cooking on low when I have the time—it allows the flavors to develop more deeply and keeps the chicken incredibly moist.
Once the chicken is fall-apart tender, remove it from the slow cooker and shred it using two forks or your hands (let it cool slightly if needed). Return the shredded chicken to the slow cooker and stir in the fresh lime juice. Taste and adjust seasoning if needed—the lime juice adds brightness and balances the richness of the coconut milk.
Add the packed spinach to the slow cooker and stir it in—it will look like a lot at first, but it wilts quickly. Cover the slow cooker and let it sit for about 15 minutes until the spinach is completely wilted and tender. This approach keeps the spinach fresh-tasting and bright rather than overcooking it during the entire cooking process.
Ladle the creamy coconut chicken over cooked rice in bowls. Top each serving with the fresh cilantro from the ingredient list and serve immediately. The cilantro adds a final burst of freshness that complements the warm spices beautifully.
