Directions

1. Preheat oven to 475 degrees. Finely chop garlic, and sprinkle with salt. Using a chef's knife, press flat side of blade back and forth across garlic to make a paste. Transfer to a small bowl; stir in thyme and 1 tablespoon oil. On a large rimmed baking sheet, toss potatoes with garlic mixture; bake until browned on underside, 20 to 25 minutes.
2. Meanwhile, heat a large skillet or grill pan over high. Season steaks with salt and pepper, and cook (in two batches if necessary) until medium-rare, 3 to 6 minutes per side (depending on thickness of steak). Transfer to a plate to rest.
3. While steaks rest, make salad: In a large bowl, whisk together vinegar, Dijon, and remaining oil; season with salt and pepper. Add watercress, and toss to combine. Serve steaks with potatoes and salad.