Dina, I would simply add some chipotle peppers in adobo to some mayo - maybe add a bit of garlic and lime juice too.
For the cilantro sauce you could make a pesto using parsley and cilantro versus basil. Or, you could take some cilantro, kosher salt, garlic, olive, and simply blend in a food processor. Some lime might be nice in there too and it would certainly compliment the fish. Instead of the oil you could heat some butter and olive oil, add some shallots and then add the rest of the ingredients.
As you can tell I don't have an actual recipe - just putting some ideas out there.
"Count yourself...you ain't so many" - quote from Buck's Daddy