In a small bowl, mix together olive oil, Napoleon® Classic Steak Spice, Shiraz, garlic and thyme. Rub the steaks with the seasoning paste, pressing the seasoning into the meat to adhere. Cover and set aside until needed.
Drain Portobello mushrooms from water and pat dry with paper toweling. Slice onions into 4 wedges through the root end. Season mushrooms and onion wedges with olive oil, and Napoleon® Classic Steak Spice to taste.
Preheat grill to high heat.
Grill mushrooms and onions for 10-18 minutes, turning occasionally until lightly charred and tender. Set aside on the warming rack of the grill to keep warm.
Place steaks onto preheated grill and sear for 3-4 minutes per side. Reduce heat to medium and place steaks on the warming rack of the grill. Close lid and allow steaks to roast for an additional 10-15 minutes for medium-rare doneness, basting every few minutes with Napoleon® Steak Sauce.
Remove steaks from grill and allow to rest for 1-2 minutes.
Remove mushrooms and onions from grill and slice into 1-2 inch pieces.
Slice steaks into 1” thick slices across the grain and arrange on a platter. Top with the grilled onions and mushrooms and crumbled blue cheese. Serve immediately. Try serving these succulent steaks with some Shiraz.