Preheat the oven to 425 degrees F. (The high heat allows the food to cook rapidly while promoting caramelization.)
In a large mixing bowl, combine the diced potatoes, oil, and the packet of Lipton onion soup mix. Toss until the potatoes are evenly coated.
Place the potatoes in one even layer on a large, rimmed baking sheet. Bake in the preheated oven for 20 minutes.
While potatoes are baking, prepare the chicken and green beans.