In a well ventilated area, heat large cast iron pan on stove until scorching hot to the touch.
Melt 2 tbsp butter in pan.
Add sliced potatoes to pan and cook, stirring occasionally to prevent burning, until crispy golden brown - about 6 minutes.
Remove potatoes from pan and lay on metal baking sheet, covered in foil.
Generously sprinkle salt and pepper over sliced steak bites.
Add other 2 tbsp clarified butter to pan and swirl to melt.
Add steak bites to pan, making sure they aren't overcrowded.
Sear on each side until browned all over, about 3 minutes, and add mushrooms to pan.
Stir to cook until mushrooms have slightly browned.
Add potatoes back to pan and sprinkle with Italian herbs. If needed, drizzle with olive oil to toss and continue to cook for 1-2 minutes until steak is at your preferred doneness.
When steak is cooked and potatoes are golden brown and crunchy on the outside/soft in the middle, top with blue cheese crumbles.
Top with chives if desired.
Serve immediately.