1.) Position rack in upper third of the oven & preheat to 400. On rimmed baking sheet, toss chicken with 1 Tbs EVOO, thyme & 1/2 tsp each salt & pepper; roast for 20 minutes. 2.) Meanwhile, in a medium bowl, combine mushrooms, onion, peas & remaining 1 Tbs EVOO; season with salt & pepper. Add veggies to chicken & cook 25 minutes more.