Roasted Beet Salad with Watercress & Tomatoes

• 6 unpeeled beets, scrubbed
• 2 tbsp sherry vinegar or red wine vinegar
• ¼ tsp Freshly ground pepper
• ½ tsp Kosher salt
• ½ c extra virgin olive oil
• 1 c grape or cherry tomatoes, halved lengthwise
• 1 small red onion, halved and sliced into thin half moons
• 2 bunches (about 8 oz) watercress, stemmed

Preheat oven to 400ºF. Wrap each beet in aluminum foil and place on a rimmed sheet pan. Bake until beets are barely tender when pierced with a small, sharp knife, about 1 hour. Let cool until easy to handle. Slip off beet skins. Halve beets and cut into 1/2-inch-thick half-moons.

Whisk vinegar, salt and pepper in a medium bowl. Gradually whisk in oil. Add beets, tomatoes and red onion and toss well. (Salad can be made to this point up to 1 hour ahead, or refrigerated for up to 8 hours.)

Just before serving, add watercress and toss again. Reseason with salt and pepper. Serve at room temperature or chilled.