- Two 1 1/4-pound racks of lamb, bones frenched
- Kosher salt and freshly ground pepper
- 7 tablespoons extra-virgin olive oil
- 1 shallot, finely chopped
- 1 1/2 tablespoons Dijon mustard
- 1/4 cup red wine vinegar
- One 19-ounce can cannellini beans, drained and rinsed
- 2 bunches watercress (10 ounces), stems trimmed
Preheat the oven to 425°. Season the lamb with salt and pepper. In a very large skillet, heat 1 tablespoon of the olive oil until shimmering. Add the lamb fat side down and cook over moderately high heat until well browned, about 4 minutes. Turn the lamb fat side up and roast in the oven for about 18 minutes, until medium-rare. Transfer the lamb to a work surface and let rest for 5 minutes.
Meanwhile, pour off all but 1 tablespoon of oil from the skillet. Stir in the shallot and cook over moderately low heat, until tender, 1 minute. Whisk in the mustard and vinegar. Gradually whisk in the remaining 6 tablespoons of olive oil. Add the beans to the skillet, season with salt and pepper and stir to combine.
Spread the watercress on a serving platter. Pour the white beans over the watercress. Cut the lamb between the ribs into chops. Arrange the chops on top of the white beans and serve.