Heat skillet with 1 tbsp olive oil, 1 tbsp butter and 2 cloves minced garlic on medium-high heat.
Pat dry the steak on all sides with a paper towel.
Add salt to each side of the steak.
Sear each side of the steak for 2 minutes.
While searing the steak, preheat the oven to 350 degrees.
Place steak in an oven-safe dish and pour pan drippings on top.
Bake for 10 minutes (depending on thickness).
Cut stems off cilantro and parsley.
Slice red onion.
Place cilantro, parsley, red onion 1/3 cup olive oil, 3 cloves minced garlic, 3 tbsp lime juice, 2 tbsp red wine vinegar, 1/2 tsp salt and 1/2 tsp black pepper in the blender on high for three minutes.
Slice steak against the grain.
Serve steak with chimichurri sauce on the side or on top.