Pat the chuck roast cubes dry with paper towels to remove excess moisture.
Season the steak cubes evenly with kosher salt and freshly ground black pepper.
Heat the olive oil in a large skillet over medium-high heat until shimmering.
Add the steak cubes to the skillet in a single layer, working in batches if necessary to avoid overcrowding.
Sear the steak bites for 2 to 3 minutes on each side until a golden-brown crust forms and the internal temperature reaches your desired doneness (about 130°F for medium-rare).
Remove the steak bites from the skillet and set aside on a plate.
Reduce the heat to medium and add the unsalted butter to the same skillet.
Once the butter has melted, add the minced garlic and sauté for 1 to 2 minutes until fragrant, stirring constantly to prevent burning.
Return the steak bites to the skillet and toss them in the garlic butter sauce for 1 to 2 minutes to coat evenly and warm through.
Sprinkle the finely chopped fresh parsley over the steak bites and give a final toss.
Serve immediately while hot.