In a large skillet over medium heat, heat coconut oil. To the skillet, add the chicken and season with salt and pepper, nutmeg and cardamom. Cook for 15 minutes, until chicken is cooked through.
In a small bowl, whisk the next 3 ingredients (coconut milk through orange juice) until smooth. Pour sauce over the chicken and cook for 15 minutes, until the sauce starts to thicken.
Using a slotted spoon, spoon the chicken into collard leaves. Top the chicken with onions and serve.