Heat oven to 375°F. Lightly grease 13x9-inch (3-quart) baking dish.

Cook noodles in salted water as directed on package for minimum cook time. Drain; place noodles in large bowl.

Meanwhile, in 10-inch skillet, heat oil until hot. Cook onion in oil until soft and translucent. Season lightly with salt. Add chicken stock; heat to simmering. Stir in cream cheese until melted and combined. Stir in 2 tablespoons of the ranch dressing mix. Pour mixture over noodles. Fold in chicken, bacon and frozen peas. Spread in baking dish.

In small bowl, mix melted butter, bread crumbs and remaining 1 teaspoon ranch dressing mix until well coated. Spread over noodle mixture.

Bake about 20 minutes or until top is crisp and sauce is bubbling. Let stand 5 minutes before serving.