Heat a large covered cast iron pot over medium-high heat, and add the avocado oil. Place chicken thighs skin side down in the pan to crisp the skin to a golden brown.
Into the skillet, add the onions and garlic. Saute the vegetables over medium heat. Add the spices, chicken stock, and SunButter into the pot, and whisk until combined and smooth.
Bake the chicken for 30 minutes covered. Remove the cover, and continue baking the dish for 10 minutes. Garnish with cilantro and lemon slices to serve.