Preheat your oven to 375°F (190°C).
In a small bowl, mix together the soy sauce, honey, rice vinegar, grated ginger, and minced garlic.
Heat the sesame oil in a saucepan over medium heat. Add the soy sauce mixture and bring to a simmer.
In a separate bowl, mix the water and cornstarch to create a slurry. Add this to the saucepan and stir until the sauce thickens.
Place the cod fillets in a baking dish and pour the sauce over them.
Bake in the preheated oven for 15-20 minutes, or until the fish flakes easily with a fork.
Garnish with sliced green onions and sesame seeds before serving.
