Mix oil, salt, brown sugar, soy sauce, red wine vinegar and red pepper flakes with a whisk in a large baking dish or bowl. Trim any excess fat off of the flank steak and cut into two if necessary. Add steak to the bowl and allow to marinate on the counter for 20 to 25 minutes.

Cut up herbs and garlic and mix in a small bowl with 1/2 of a tub of Land O Lakes® Butter with Olive Oil. Place in the refrigerator.

Heat grill pan on medium high (oil pan if necessary) for 5 minutes. Add steaks to the grill pan and cook for 3 to 4 minutes on each side. Turn again and cook about 1 minute on each side. Remove from pan and place on a clean plate and allow meat to rest for about 5 to 6 minutes before slicing. (Make sure to slice against the grain at an angle.) Serve topped with Chimchurri Butter.

Serve with mashed potatoes, vegetables and a salad if you wish.