If you have a food processor, place leeks, parsley, mint, thyme, garlic, and lime zest inside with an S-blade on. Blitz a few times, until the ingredients are finely ground up. If using a Thermomix 10 seconds, speed 5. Alternatively, chop everything very finely using a knife.
Transfer to a large mixing bowl together with the mince, salt and pepper. Mix really well, until well incorporated. If using a Thermomix, 40 seconds reverse speed 3 (you may need to use the spatula to help mix it through).
Heat coconut oil in a large skillet over medium-high heat. Roll the mixture into small meatballs, about 20g each, smaller than a Ping-Pong ball. Fry the meatballs for 7-8 minutes, turning them throughout so they go golden-brown on all sides.
In the meantime, add the olive oil, the other part of the leek, lemon peel, carrot and potato to a medium saucepan. Sauté for a few minutes, then add the garlic, cumin, star anise, chicken stock and fish sauce. Season with some salt and pepper and bring to boil.
Add the meatballs and cook over medium heat, covered, for 3-4 minutes. Prepare the kale and add to the soup, stir through and cook for a further 5 minutes, covered. Test the potato and once soft, remove from the heat and add the lime and lemon juice.
Stir and taste for salt. Let it sit for 5 minutes off the heat before serving.