Preheat the oven to 425°F.
Toss the halved baby potatoes with olive oil, rosemary, thyme, salt, and pepper on a baking sheet.
Roast the potatoes for 25 to 30 minutes, tossing halfway, until golden and fork-tender.
While the potatoes roast, pat the steak cubes dry and season generously with salt and pepper.
Heat 1 tablespoon of butter in a skillet over high heat until sizzling.
Sear the steak bites in a single layer for 2 to 3 minutes per side until a deep brown crust forms, working in batches if needed.
Reduce the heat to medium and add the remaining butter and minced garlic to the skillet.
Toss the steak bites in the garlic butter for 1 minute until fragrant and glossy.
Sprinkle with fresh parsley.
Plate the steak bites alongside the roasted potatoes and spoon any extra garlic butter over the top.