Preheat the oven to 350 F (180 C). In a small saucepan, melt the butter. Add the Onion Chive Dip mix and mushrooms and cook over medium-low heat until the mushrooms start to render their juices, about 2 minutes.
Add in the flour and stir. Pour in the wine and stock, stirring for 1-2 minutes until thick and smooth. Stir in the cream and the seafood until warm.
Add a squeeze of fresh lemon juice to brighten the flavours. Transfer into the baker, sprinkle with cheese. Bake for 5 minutes, then broil for 5-8 minutes. Serve with crusty bread.