In a small bowl combine all ingredients together and whisk. Set aside.
FOR THE FILLET:
Preheat oven to 425 F.
Season fillet with salt and pepper to taste.
Heat oil in a cast iron skillet on the stove top over medium-high heat.
Cook fillet for 2 minutes per side.
Immediately transfer pan to the oven and cook for 6 to 9 minutes, depending on the desired doneness. 7 minutes for rare, 8 medium-rare and 9 medium. Alternatively, check the temperature of the meat. Temperature may vary depending on the size of the fillet.
Remove from the oven, transfer fillet to a plate. Cover with aluminium foil and let it rest for 5-7 minutes. Slice.
FOR THE SALAD:
Place mixed greens in a salad bowl.
Add pomegranate seeds, hazelnuts, onions, chopped apple, blue cheese and fillet. Pour dressing on top.
Cooking times can vary. You can also check the temperature of the meat and refer to this picture for more info.