Pat the steak pieces dry with a paper towel to remove any excess moisture, to help achieve a better sear.
Season the steak with salt and freshly ground black pepper according to taste. I season fairly generously – don't be afraid to season!
In a very large skillet, heat olive oil over medium-high heat. Make sure oil is hot, then add steak to the skillet and cook for about 2 minutes without moving, to get a good sear.
Then flip and cook for 1 to 2 minutes more. These bites aren't huge, so they'll cook fast. You'll only need 3 to 4 minutes of total cook time for medium-rare steak bites. Plus, the bites will continue to cook after you remove them from the heat.
Remove steak from the skillet and set aside.
The skillet should be very hot by now, and you don't want to burn the butter in this step. First reduce the heat to medium-low. Then remove the skillet from the heat for 30 to 60 seconds to let it cool slightly. Place the skillet back on the heat and add the butter; let it melt.
Stir the garlic into the melted butter and sauté for 1 to 2 minutes, stirring frequently, until softened and fragrant. Do not let the butter and/or garlic turn brown or burn.
Stir in the Worcestershire sauce, a few sprigs of fresh thyme, and red pepper flakes. Cook for an additional minute to allow the flavors to meld together.
Return the cooked steak to the skillet and toss in the garlic butter sauce to coat evenly. Let the steak bites warm for 30 to 60 seconds. Take care to not over-cook.
Remove skillet from heat. Serve immediately, straight from the skillet. Or transfer the steak bites to a serving dish. If desired, remove the cooked thyme sprigs – and garnish with fresh thyme sprigs or leaves.