Cut steak into 2-3" pieces. Rub evenly with avocado oil then season well on all sides with blackened seasoning. Allow steak to sit for 10-15 minutes at room temp.

Peel potatoes and quarter them. Place them in a bowl of cold water for 10 minutes to remove excess starch. Drain, then place in a pot of salted water and boil until fork tender.

In a large skillet over medium-high heat, add 2-3 tablespoons avocado oil and add steak pieces in the hot skillet. Cook undisturbed for about 2 minutes until golden. Flip once, and continue to cook for 1 more minute, then reduce heat to low and cook for 1 additional minute. Remove steak and keep in a bowl.

Add in 3 tablespoons of butter and 1 tablespoon of minced garlic to the pan and sauté until fragrant. Toss the steak in the garlic butter and cook for another minute before keeping warm.

In the same pan, add 2 more tablespoons of butter and remaining minced garlic. Sauté until fragrant, then slowly whisk in heavy cream and bring to a simmer, allowing it to reduce for 3-5 minutes.

Drain excess water from the potatoes, add melted butter and cream, and mash until smooth. Incorporate cheese and seasonings.

Into the cream sauce, add red pepper flakes and scallions, then whisk in the parmesan cheese. Adjust seasoning as needed and serve steak over the mashed potatoes, spooning over the parmesan cream sauce.