Heat oven to 400 degrees F.
On a large rimmed baking sheet (or in a large roasting pan), toss the apples, leeks, rosemary, oil, 1/2 teaspoon salt, and 1/4 teaspoon pepper.
Season the chicken with 1/2 teaspoon each salt and pepper and nestle, skin-side up, among the apples and leeks.
Roast at 400 degrees for 40 to 45 minutes, until the chicken is cooked through and the apples and leeks are tender.
Before serving, sprinkle pomegranate seeds over the chicken, apples and leeks.
This recipe incorporates three of Rosh Hashana's symbolic foods in this tasty, simple main course.