In a bowl combine ground beef, chopped mushrooms, salt, pepper, seafood and mix until incorporated. Form into 6 patties and chill in refrigerator for at least 1 hour.
Heat a cast iron pan over medium heat, add a little olive oil to the pan and cook patties for 4 minutes on each side.
While the patties are resting make the gargonzola mixture. In a bowl mix softened butter with crumbled gargonzola cheese.
Apply mayo to both sides of potato bun and layer patty, a dollop of kc BBQ sauce, tomato, onion and top with gargonzola mixture.
