Prep work:

Season steaks with salt & pepper and coat with a little olive oil and let steaks come to room temp before starting to cook.

Slice onions and mushrooms to preffrance, set aside.

Crush garlic cloves and mince very fine, add garlic (you can also add some fresh herbs like rosemary or oregeno) to 1/4 stick of room temp butter and mix well with a fork, set aside.

Cooking: Add 1 tablesppon of butter to a warm 10 inch iron skillet, Add mushrooms and onions, splash a little olive oil on top and sautee until onions are carmelized, remove from skillet and set aside.

(using the same skillet you use for the onions and mushrooms) Place steaks in hot skillet and cook for about 10 minutes with out moving them until you have a nice charred crust, then flip steaks and cook the other side until you have the same charred crust on both sides.

Note: If you like your steaks well done you may need to finish the steaks off in the oven @ 400f for 5-10 minutes.

Place steaks on plates spoon some garlic butter on top of the steak and then top off with the mushrooms and onions (you may want to pour any remaining juices from the skillet on the steaks as well), let steaks rest about 5 minutes, this will ensure the juices stay in the steak and not drain on your plate, then dig in, Hope you Enjoy.