Melt the coconut oil in a large skillet set over medium-high heat. Add the onion and cook it until softened and slightly colored, about 2 minutes. Add the chicken, salt and pepper and cook until the chicken turns completely opaque.
Add the squash, chicken stock, garam masala and curry to the pan, cover loosely and simmer until the squash is fork tender, about 25 minutes
In a small glass measuring cup, mix the coconut milk, tapioca starch and lime juice and mix well; Add that to the skillet, stir until completely incorporated then bring to the boil and continue stirring until the sauce starts to thicken, about 1 minute.
Add the spinach and delicately mix it in until completely wilted, then kill the heat and stir in the tomato.
Serve piping hot with cooked jasmine or basmati rice (or cauli-rice for strict paleo / squeaky clean)