Pat chicken breasts completely dry with paper towels.
Season both sides with kosher salt, black pepper, and garlic powder.
Rest at room temperature for 30 minutes.
Heat oil in skillet over medium-high heat until shimmering.
Add butter and swirl until melted and bubbly.
Add chicken breasts, leaving space between each piece.
Cook undisturbed for 5-6 minutes until golden brown.
Flip and cook second side for 5-6 minutes.
Reduce heat to medium, cover pan, and cook until internal temperature reaches just under 165°F.
Rest for 2-3 minutes before serving or slicing.