Melt some cooking fat in a large saucepan placed over medium-high heat.
Cooking fat
Add the leeks to the saucepan and cook until soft, about 10 minutes.
1 medium leek
Season to taste with salt and pepper.
Sea salt and freshly ground black pepper
Add the chicken stock and water and bring to a boil while stirring.
4 cups chicken stock, 1 cup water
Lower the heat and let simmer for about 15 minutes.
Add the chicken and coconut milk and cook until the whole soup is warmed through.
½ cup coconut milk, 2 cups cooked chicken
Remove one ladle of warm broth from the soup. Mix it with the tapioca starch in a small bowl, and then slowly add the mixture back to the soup while stirring until the soup reaches your desired consistency.
2 cloves garlic, 1 tbsp. tapioca starch
Adjust the seasoning and serve.