Preheat the oven to 500 degrees
Cut up and cube squash and root vegetables into similar sizes and place in a large bowl
Combine melted butter, olive oil and chopped herbs, and pour over vegetables
Toss to evenly coat all veggies, and then spoon them out onto a large baking sheet, reserving the extra butter & oil mix if you are cooking chicken as well
Season veggies with salt and pepper
Toss chicken in remaining butter oil mixture, and place on a separate baking sheet
Cook the veggies at 500 degrees for 20 minutes, checking on their doneness after about 15 minutes just to make sure they aren't getting over cooked. Depending on the size of your veggies, they may need to cook an additional 5 minutes, and are done when fork tender
Lower the oven to 400 degrees and cook the chicken thighs for 20 minutes, checking on doneness after 15 minutes. Cook until internal temperature reaches 165 degrees, although most of the time I can tell their doneness by how firm they are to the touch, and if they feel bouncy or not. If firm, they are usually done.