Boil the potatoes in salted water until tender, about 15 minutes. Drain and mash with milk and butter. Season with salt and pepper.
Season the steak bites with salt and pepper. Heat a skillet over medium-high heat and add the butter.
Cook the steak bites in the skillet for 2-3 minutes on each side until browned. Remove from the pan and set aside.
In the same skillet, add the minced garlic and cook for 1 minute until fragrant. Return the steak bites to the skillet and toss to coat in the garlic butter.
Serve the steak bites over the mashed potatoes. Garnish with chopped parsley and enjoy!