Pull the steaks out of the refrigerator 1 hour prior to cooking. Heat the oven to 400 degrees. About 5 minutes before you’re ready too cook, heat a cast iron skillet over medium-high heat. Season the steaks on all sides with salt and pepper. When the skillet is lightly smoking, add the oil and steaks to the pan, making sure there is space between each steak. Sear on one side until a browned crust forms, about 5 minutes. Flip the steaks and cook for 2 minutes. Add the garlic, thyme and 2 tablespoons of the butter. Swirl the butter in the pan, then transfer to the oven. Cook until an instant-read thermometer reads 120 degrees, 5 to 7 minutes. Remove the skillet from the oven and return to a burner over medium heat. Add the remaining butter, let it melt, and then use the butter to baste steaks constantly until the thermometer reads 125 degrees (for medium-rare).