Mix the olive oil, garlic, lemon zest, herbs, and salt into the softened butter with a fork. Place a spoonful on the serving plate for each steak, then roll the rest into a log in plastic wrap and refrigerate.
Pat the steaks dry with a paper towel. Evenly coat steaks with olive oil and season generously on both sides with kosher salt. Pepper now or later, personal preference based on FAQ reading.
Set up for direct high heat, as hot as your grill will go. Charcoal: full chimney banked tight under the cooking area. Gas: all burners high, lid closed, 10 to 15 minutes.
Place the steaks directly over the heat with the lid open. Flip every 30 seconds, landing on a fresh, hot spot on the grate each time.
Start checking around the 7 minute mark. Pull at 120°F for medium rare or 130°F for medium.
Set each steak on a slice of compound butter and rest 5 to 10 minutes, uncovered. No foil tent, since trapped steam softens the crust.
Slice against the grain, season with fresh cracked pepper, and serve immediately.
Notes
Pull temps assume 8 to 10 degrees of carryover from a high-heat sear. Low and slow cooks carry over much less, so these numbers are specific to hot-and-fast grilling.
Keep the lid open the entire cook. You're flipping constantly, so the steak cooks from direct heat only.
Rest uncovered. A foil tent traps steam and softens the crust you just built.
The butter recipe makes a full log, far more than two steaks need. That's intentional, since it freezes for months. Full details in my compound butter for steak post.
This method is best for steaks under 1½ inches thick. For thicker cuts, use the reverse sear instead.