Choose a steak (about 1 to 1.5 inches thick)
Pat steak dry with paper towels
Season generously with salt and black pepper (add garlic powder or other seasonings if desired)
Heat a cast-iron frying pan over medium-high heat for 5 to 10 minutes
Add a high-smoke-point oil (about 1 to 2 tablespoons), swirl to coat
Place steak in the pan and cook without moving
Cook for about 3 to 5 minutes per side for medium-rare (adjust for thickness and preference)
Flip steak once using tongs
Add butter (2 to 4 tablespoons), plus optional aromatics (2 smashed garlic cloves, thyme/rosemary) in the last 1 to 2 minutes
Baste by spooning melted butter over the steak for 30 to 60 seconds
Check doneness with an instant-read thermometer
Target internal temps: 125°F for rare, 135°F for medium-rare, 145°F for medium, 160°F for well-done
Transfer steak to a plate or cutting board
Rest 5 to 10 minutes
Slice against the grain and serve