Corn and Cod Green Curry

Name: Corn and Cod Green Curry
Ingredients: 5 ears of corn (or 5 cups frozen corn kernels); 1 (2-inch) piece of ginger (no need to peel); 4 ounces (⅓ cup) green curry paste; 2 tablespoons coconut oil or neutral oil such as grapeseed; 1 (14-ounce) can full-fat coconut milk; 1 tablespoon fish sauce, plus more as needed; 1½ pounds cod, cut into 1 ½-inch pieces; 3 baby bok choy, thinly sliced; Juice from 1 lime (2 tablespoons); Basil or cilantro leaves, for serving; Thinly sliced Thai bird or serrano chile, for serving (optional)