1/2 C. ketchup
1 tsp. prepared horseradish (can be found in fridge section of store, Usually in the dairy area. I know it is an odd place.)
1/4 tsp. Worcestershire sauce
1 smidgen of ground cayenne or 1-2 drops hot pepper sauce.
Mix and serve or store covered in the fridge. Double and or triple the recipe for serving more people.
Updated note: If you get burnt out on this and still have leftovers. Add some mayo to it and you get a smooth creamy tarter or thousand island like sauce. Yum.
Try this sauce with other fish and or shell fish. Try warm or cold to see how you like the sauce or fish best.
I have read that you can freeze the pho fish for later use. I have never done that. I do know that the best way to defrost fish/shell fish is by placing in bowl of cool water for about 15 minutes or so depending on how much you are thawing. Serve or place in fridge until serving soon.