2 1/2 pounds top sirloin Kosher salt and fresh black pepper for seasoning the steak 4 tablespoons butter, divided 2 tablespoons olive oil, divided For The Garlic Parmesan Sauce: 1 stick of butter, melted and cooled 1 tablespoon chopped garlic 1/4 cup grated parmesan cheese 1/4 cup mayonnaise 1/2 teaspoon kosher salt 1/4 teaspoon black…