Preheat oven to 200°C/180°C fan-forced.

Discard necks from quails. Wash quails under cold water; pat dry with absorbent paper.

Halve lemon; cut one lemon half into four wedges. Place one lemon wedge and a quarter of the butter inside each quail. Tuck legs along body, wrapping tightly with bacon rasher to hold legs in place.

Place quails in medium flameproof casserole dish; drizzle with one tablespoon of the muscat and juice of remaining lemon half. Roast, uncovered, about 25 minutes or until quails are browned and cooked through. Remove quails from dish; cover to keep warm.

Meanwhile, boil, steam or microwave beans until tender; drain. Cover to keep warm.

Return dish with pan liquid to heat, add remaining muscat and stock; stir until sauce boils and reduces to about ½ cup. Add grapes; stir until heated though. Serve quail on beans topped with grape sauce.