Wash the pak choy
Rinse the Pak Choy very well under cold running water, separating the leaves slightly so any grit trapped near the base washes away. Trim off the root end, then cut any larger heads in half lengthwise so everything cooks at the same rate. Shake off excess water and set aside.
Prep the aromatics
Finely zest the Lime, then cut it in half and squeeze out the juice. Peel and grate the Ginger, and finely mince the Garlic. Keep everything nearby so it is ready to go into the pan together.
Build the poaching liquid
Pour the Coconut Milk into a large deep pan or skillet and stir in the lime juice, lime zest, ginger, garlic, Soy Sauce, and a pinch of Chili Flakes if you want a little heat. Set the pan over medium heat and warm the mixture, stirring occasionally, until it reaches a gentle simmer. You want small bubbles around the edges, not a full boil.
Poach the cod
Lower the Cod Fillets into the simmering coconut-lime liquid in a single layer. Adjust the heat so the liquid stays at a low, steady poach, then cover the pan and cook for 6 minutes. Check the cod; if it is not quite opaque all the way through, give it up to 2 minutes more. The fish is ready when it flakes easily with a fork but still looks moist.
Wilt and serve
Tuck the pak choy into the poaching liquid around the cod and cook for 2 minutes, just until the stalks are crisp-tender and the leaves are wilted but still bright. Carefully lift the cod and pak choy into shallow bowls or plates, then spoon plenty of the coconut-lime sauce over the top and serve straight away while hot.
















