Nice, looks easy enough. I'll be using fresh garlic, removing the mushrooms and doing crawfish instead of lobster. This method of making Roux is extremely simple and yet different than how a Cajun taught me via butter instead of oil and baking it. But he was doing it for Gumbo and never showed me for a white sauce. The Seafood Portofino was my favorite dish and actually the only entree at Olive Garden that I ever got for as long as I can remember. Now I'm finally going to make it at home from scratch, or something close to it anyhow
No need for a boxed stock. Next time take the shells of the lobster and shrimp and boil in water reducing down until the flavor is extracted from the shells