Roasted Brussels Sprouts and Grapes with Walnuts

There are many versions of my favorite Brussels sprout dish out there in cyberspace, but this one from Martha Stewart — originally from Whole Living magazine, where I first found it — sums it up nicely. This is a go-to fall/winter recipe for me, and it’s a definite crowd pleaser that looks pretty on a plate.
24 ounces Brussels sprouts (about 8 cups), halved or quartered if large
24 ounces grapes
2 tablespoons extra-virgin olive oil
4 tablespoons fresh thyme
Coarse salt and freshly ground pepper
2 teaspoons balsamic vinegar
1/2 cup walnuts, toasted and coarsely chopped
Heat oven to 450 degrees. On two rimmed baking sheets, toss Brussels sprouts and grapes with oil and thyme. Season with salt and pepper. Roast, until caramelized and tender, about 20 minutes.
Drizzle each tray with 1 teaspoon vinegar and scrape up any caramelized bits with a wooden spoon. Toss in walnuts.