Preheat oven 375°F.
For the potatoes, heat a large skillet over medium-high heat with the canola oil. Add the potatoes to the hot oil, season with salt and pepper, and brown on all sides. Add the butter, crushed garlic, rosemary and 1 cup chicken stock. Bring up to a bubble and turn down to a gentle simmer. Simmer until potatoes are tender, about 45 minutes, adding more stock if it goes completely dry.
For the salsa, place all ingredients in a food processor and pulse until a chunky consistency. Set aside.
Heat a large, cast iron skillet over medium-high heat with the canola oil. Season the steak on each side with some salt and pepper. Once the skillet is hot, add the steaks and brown on each side for about 2 minutes or until deep golden brown. Transfer skillet to preheated oven and continue to cook for about 5-7 minutes or until medium-rare.
Remove skillet from oven and return to cook top over medium heat. Add butter, thyme sprigs and crushed garlic to the pan. Once butter has melted, baste steak with a spoon in the herb-garlic butter for about 1 minute. Remove steak from pan and let rest a few minutes before slicing against the grain.
Serve steak topped with salsa verde with potatoes alongside.