Preheat large skillet over medium heat with 1 tbsp ghee. Add in onions, season with a pinch of kosher salt and saute until translucent. Add in green bell pepper slices, season with more kosher salt and black pepper, mix with onions and saute for about 5 minutes or until green bell peppers start to soften.

Turn the heat up to medium-high, scoot onions and green bell peppers to one side of skillet. Add in 1 tbsp of ghee and the thinly sliced steak. Season with nutritional yeast (optional), garlic powder, and a generous amount of kosher salt and black pepper. Let the steak sit for a couple of minutes and then mix in with onions and green bell peppers.

Mix in the mushrooms when the steak is about 75% cooked through. Stir and cook until mushrooms have soften and steak is cooked through. Taste to see if you need additional kosher salt and black pepper.