Add two tablespoons of butter to a large skillet over medium-high heat. Melt the butter, then add the shrimp and scallops to the hot pan.
Sauté the shrimp and scallops for about a minute, just long enough to sear the outside of the seafood.
Add a splash of white wine to deglaze the pan, then add the heavy cream, chicken broth, dijon mustard, and seasonings to the pan.
Sauté the mixture for one minute, then remove the shrimp and scallops from the pan. Set aside until needed.
Add two tablespoons of butter dredged in flour (beurre manie) to the seafood sauce. This will thicken the sauce. Let it simmer over low heat to thicken.
Remove the pan from the heat and add the scallops, shrimp, and crab meat to the sauce. Mix until seafood is coated and set aside until needed.