Heat oven to 450°F. Set aside 2 tablespoons of the balsamic glaze and brush or spoon the remaining 1 tablespoon on the chicken. Season with salt and pepper.

• Peel the onion and cut into ½-inch rounds.

Drizzle a bit of oil on a baking sheet. Add the onions and turn to coat lightly with the oil. Season with salt and pepper. Put the chicken, skin-side up, next to the onions. Roast on a rack in the middle of oven until the onions are tender and beginning to brown and the chicken is cooked through, about 15 minutes. Check the chicken after 10 minutes and turn the onions.
Meanwhile, prepare the beans.

Trim the stems from the beans. In a 12-inch frying pan over medium-high heat, warm 1 tablespoon oil until hot but not smoking. Add the beans, season with salt and pepper, and cook, stirring once or twice, until charred and tender, about 5 minutes.

• While the beans cook:

• Cut the pepper into strips.
• Rinse and chop the herbs.
• Whisk 1 tablespoon oil into the remaining glaze.

In a mixing bowl, combine the roasted onions, beans, pepper strips, and herbs. Add the glaze and toss well.

Transfer the onions and beans to serving plates and serve with the roasted chicken.

Try grilling the chicken and onions for the salad instead of roasting them. If you're worried that the balsamic glaze might darken the chicken too quickly, brush it on the meat after it's cooked.