01 -
Add the steak cubes to a large bowl and sprinkle with salt, black pepper, and red pepper flakes. Toss to coat and let rest at room temperature for 30 minutes.
02 -
Drizzle the avocado oil over the steak cubes and toss until well coated.
03 -
Heat a large cast-iron skillet over medium-high heat. Once hot, add half of the steak cubes in a single layer. Cook for 2-3 minutes, flip, and cook for 2-3 minutes more. Transfer to a prepared baking sheet and tent with foil. Repeat with the remaining steak cubes.
04 -
Reduce the heat to low and add the butter to the skillet. Once melted, stir in the garlic and cook for 30 seconds, or until fragrant. Remove from heat.
05 -
Return the cooked steak cubes to the skillet, tossing to coat them in the garlic butter.
06 -
Serve immediately, garnished with parsley if desired.