Mix together the water, red miso paste and sesame oil together.
In a medium pan, add whole garlic's and butter.
Heat butter over medium heat and cook garlic in the butter until the garlic's start to get golden, then remove them from the pan.
Season cod fillets with a pinch of salt and pepper per fillet.
Add to the hot butter and sear on each side for roughly 1 minute per side.
Add the miso and sesame oil mixture and simmer for roughly 4-6 minutes, this will depend if your fish is fresh or frozen.
Turn fish over half way through.
Once liquid starts to evaporate. sear each side with the reduced liquid and when fish is tender yet flaky, remove from heat and serve with red miso glaze if desired.
To make red miso glaze: Add all ingredients to a sauce pan and whisk over medium heat until sauce comes to a boil and thickens slightly. Add over fish.