01 -
Allow steak to sit at room temperature for 20 minutes. Pat dry thoroughly, then cut into 1-inch cubes. Season with salt, black pepper, and red pepper flakes if using.
02 -
Peel and cut potatoes into even chunks. Cover with cold salted water in a pot and bring to a boil. Simmer until fork-tender, approximately 15 to 20 minutes.
03 -
Heat olive oil in a large skillet over medium-high until shimmering. Add beef in a single layer without overcrowding. Sear for 2-3 minutes per side until golden brown.
04 -
Reduce heat to medium. Add butter to skillet and melt until foamy. Stir in minced garlic and Worcestershire sauce. Cook for 1-2 minutes until fragrant, then toss beef to coat evenly.
05 -
Drain potatoes thoroughly and return to hot pot. Add butter, milk or cream, salt, pepper, and garlic powder if desired. Mash to preferred consistency, adding more milk if necessary for creaminess.
06 -
Plate creamy mashed potatoes and top with garlic butter beef bites. Drizzle remaining garlic butter sauce over top and garnish with fresh parsley.