Place the steak pieces in a large bowl.
Season with salt, black pepper, and red pepper flakes. Toss until evenly coated.
Heat a large skillet over medium-high heat.
Add avocado oil to the hot skillet.
Arrange the steak in a single layer.
Cook for 3–4 minutes, stirring occasionally, until browned on all sides.
Work in batches if necessary to avoid overcrowding the pan.
Remove the steak bites from the skillet and set aside.
Carefully remove any excess liquid from the skillet.
Add the butter or ghee and allow it to melt.
Stir in the minced garlic and sauté for about 1 minute until fragrant.
Return the Garlic Butter Steak Bites to the skillet.
Toss well to coat the steak in the garlic butter sauce.
Cook for an additional 1–2 minutes.
Remove from heat and stir in the chopped parsley.
Garnish with sliced green onions and serve immediately.