I'm going to attempt to explain this in here but this could be tough sledding because I don't have much of a description. I have been to a restaurant in the Caribbean that makes a red sauce that I have had in a seafood risotto and the sauce is just outstanding. I was there this past February and my inlaws were with us. I ordered the seafood risotto again and my MIL ordered a pasta dish that had the same sauce. It's nothing like you might find in a store. It's "light" and not as tomato-ey as you might ordinarily see. It doesn't seem as RED but more pink. It's not a vodka or combination of pasta sauce with alfredo or anything like that. I'm sure there must be garlic and/or onion in it. My wife and I went to a place nearby that also has excellent food and there was a seafood risotto on the menu so I ordered it. The sauce was really close to this one I'm describing. The owner came by our table to see how we were and I said, "You just have to give me the recipe for that sauce" and he said, "Yeah, that's one of those 'I would tell you but then I would have to kill you' kind of things".

It's hard to explain but I'm wondering if there are any others out there who have experienced anything like this.
I'm going to hesitantly link to
THIS because I see that it's a bolagnese sauce that is used but then there is fish stock which I could see as a flavoring for the risotto but that doesn't explain how the same sauce ended up on my MIL's plate unless her pasta had seafood in it as well.