Heat 2 tablespoons avocado oil in a large skillet. Add diced onion and cook for 3 to 5 minutes, until translucent. Add salt, pepper and garlic powder.
Stir in shredded potatoes and cook until potatoes just begin to cook, about 4 to 5 minutes. Push hashbrown mixture to the side and place two round silicone molds into the skillet. Scoop in mixture and pack down with your hand or the back of a spatula.
Fry for about 4 to 6 minutes and carefully remove silicone rings. Flip hashbrown discs over and fry on other side until crispy and cooked through. Set aside.
Add 1 tablespoon avocado oil to the pan. Once heated, add chopped mushrooms. Season with a pinch of salt, as needed. Add spinach after mushrooms have crisped up and cook until wilted. Set aside in a small bowl.
Make hollandaise: Add egg yolks, lemon juice, dijon mustard and salt to a blender. Pulse for 5 to 7 seconds, until combined.
With mixer running on low speed, drizzle in melted ghee until emulsified.
Stack Bennys, starting with hashbrown discs, then spinach and mushrooms, poached eggs and a heavy pour of hollandaise sauce. Optional: Garnish with chopped chives.