01 -
Remove steaks from refrigerator 15-30 minutes before cooking to bring them closer to room temperature for even cooking. Slice the onion into strips and set aside. Preheat the grill to high heat.
02 -
Rub 2 tablespoons of butter over both sides of the steaks and season with freshly ground pepper. Place on preheated grill and cook for 3-4 minutes per side until desired doneness (130°F/54°C for medium-rare). Remove from grill and let rest undisturbed while preparing the sauce.
03 -
Melt remaining butter in a large pan over medium-high heat. Add sliced onions and cook until slightly charred and caramelized, about 8-10 minutes. Reduce heat to medium-low.
04 -
Add heavy cream and Worcestershire sauce to the onions, stirring to combine. Bring to a simmer and cook until slightly thickened, about 2-3 minutes, stirring frequently to prevent burning. Remove from heat.
05 -
Stir blue cheese crumbles into the sauce until completely melted. Taste and adjust seasoning with salt and pepper as needed.
06 -
Slice the rested sirloin steaks and serve with the creamy blue cheese sauce poured over the top. Garnish with additional blue cheese crumbles if desired.