Preheat charcoal or gas grill for direct cooking over medium-high heat (375°).

Melt 2 tablespoons butter in small skillet over low heat. Stir in garlic. Cook 2 to 3 minutes or until butter begins to brown. Transfer to medium bowl.

Thinly slice remaining 6 tablespoons butter. Add sliced butter, parsley, 1 teaspoon salt, 1 teaspoon sage, ½ teaspoon rosemary, and ½ teaspoon black pepper to bowl with brown butter. Beat with electric mixer on high until fluffy and whipped; set aside.

Pat steaks dry with paper towels. Season both sides with remaining 1 teaspoon salt and ½ teaspoon black pepper. Grill steaks 12 to 14 minutes or until steaks reach 130° for medium-rare doneness, turning once halfway through. Transfer steaks to cutting board. Loosely cover with foil; let rest 5 minutes.

To serve, slice steaks across the grain. Garnish with thyme and additional sage and rosemary, if desired. Serve with whipped butter mixture.