01 - Place peeled and cubed potatoes in a large pot, cover with cold water, add a pinch of salt, and bring to a boil. Reduce heat and simmer for 15–18 minutes until tender.
02 - Drain potatoes thoroughly. Add butter, warmed milk, heavy cream, salt, and pepper, then mash until smooth and creamy. Cover and keep warm.
03 - Pat steak cubes dry with paper towels. Season evenly with salt and black pepper.
04 - Heat olive oil in a large skillet over high heat. Add steak cubes in a single layer, searing 1–2 minutes per side until browned but still juicy. Remove and set aside.
05 - Reduce heat to medium. Add 2 tbsp butter to the skillet. Once melted, add minced garlic and sauté for 30 seconds until fragrant.
06 - Return steak bites to the skillet, add remaining 2 tbsp butter, and toss to coat in garlic butter. Cook for an additional minute. Remove from heat and sprinkle with chopped parsley.
07 - Plate mashed potatoes and top with garlic butter steak bites. Spoon extra garlic butter from the skillet over the dish before serving.