In a medium bowl, combine the lemon zest, lemon juice, salt, pepper, thyme, garlic and dried chilli flakes. Add the sliced chicken and stir to coat. Set aside to marinate.

Heat the coconut oil over a medium heat in a non-stick frypan. Add the sliced onion and sauté until browned.

Add the chicken and remaining marinade to the fry pan, and stir to combine with the onion. Cook until chicken is browned on both sides, stirring occasionally.

When the chicken is browned, add the kale. Cook until the kale reduces and softens, about 5 minutes, ensuring you stir occasionally.

Serve with salad, quinoa or rice right from the frypan.