Mince the garlic and finely grate the ginger after peeling.
I like mincing the garlic with a knife but if you want it even smaller to it dissolves more into the sauce use the smallest holes on a box grater or a zester.
In a small mixing bowl combine all ingredients and stir to combine. Use immediately.
You can easily double this recipe if you are planning to marinate more than one pound of fish.
Notes
You can substitute soy sauce with coconut aminos or tamari, espeically if you are avoiding gluten.
Rice vinegar is best but you could also use white wine vinegar or apple cider vinegar if that’s what you have on hand.
Sriracha is great for adding a little heat but a good substitute is 1/4 teaspoon red pepper flakes.
Fresh garlic and ginger is best but if you find buying it only for this recipe (so a very small amount) a problem you can use 1/8 teaspoon garlic powder and powdered ginger instead.
If you want to add sweetness include 1/2 teaspoon of honey or brown sugar.