If you just took the 2 ribeye steaks out of the fridge, give them 45 minutes to an 1 hour to come to room temperature. Rub both both sides of the steak with some olive oil and sprinkle a large pinch of fleur de sel and ground black pepper on both sides.
For the sauce, put the ½ packed cups mint, 1 clove garlic, ¼ cups olive oil, ¼ teaspoon salt, and 1 tablespoon lime juice in a blender or food processor and puree. If you're doing it by hand, you can mince the mint with sharp knife, then combine the ingredients in a bowl.
To cook the steak on the stove, heat a stainless steel or cast iron pan just big enough to hold your steaks over medium heat for about 10 minutes, or until very hot (there's no need to add oil). Never use a non-stick pan for searing as the high temperature will make them release a toxic gas.
Add the steaks and place a splatter shield or sheet of aluminum foil on top of the pan (if you use foil, just lay it on top and don't seal the edges). Let it cook on this side for 4 minutes. Flip and cook for another 3 minutes for a rare steak, cook longer if you want it well done.
Serve immediately with the chimichurri sauce.