Pat the steak cubes dry with paper towels and season evenly with salt and black pepper.
Heat olive oil in a large cast-iron skillet over medium-high heat until it begins to smoke slightly.
Place steak cubes in the skillet in a single layer, ensuring they are not crowded; sear for 2 minutes undisturbed to develop a brown crust.
Flip the steak bites and cook for another 2 minutes until browned on all sides, then remove steak from the pan and set aside.
Reduce heat to medium and add minced garlic to the remaining oil, sautéing for 30 seconds until fragrant.
Pour in the balsamic vinegar, soy sauce, and honey, scraping the bottom of the pan to release any browned bits.
Simmer the liquid for 2 to 3 minutes until the sauce has reduced by half and thickened into a glaze.
Whisk in the butter until melted and fully incorporated into the sauce.
Return the steak bites to the skillet and toss thoroughly to coat in the balsamic glaze.
Remove from heat, garnish with fresh parsley, and serve immediately.