Cook the Steak: In a large skillet, heat olive oil over high heat. Add the steak cubes in a single layer, making sure not to overcrowd the pan. Cook for 2-3 minutes on each side until browned and cooked to your desired doneness. Remove the steak from the skillet and set aside.
Make the Garlic Butter: In the same skillet, reduce the heat to medium. Add the unsalted butter and minced garlic. Cook until the butter is melted and the garlic is fragrant, about 1-2 minutes. Stir in the dried thyme, dried rosemary, sea salt, and black pepper.
Combine Steak and Garlic Butter: Return the steak bites to the skillet and toss to coat in the garlic butter. Cook for an additional 1-2 minutes until the steak is warmed through.
Serve
Assemble the Plate: Divide the mashed potatoes among plates. Top with garlic butter steak bites and a side of green beans.
Garnish: Garnish with chopped fresh parsley and serve immediately.