Spatchcock indirect @400 grate temp in a tray of veggies

I decided to play around a little with tonight's dinner.  All my previous spatch's have been direct at about 400 grate.  Tonight I wanted to do a meal-in-a-single-pot concept so I put the spatchcock chicken on top of onion, celery, roma tomatoes and baby red potatoes.  I put a butter / poultry seasoning / dill / white pepper mix under the skin of the bird.  I sprinkled the veggies with salt and pepper and poultry seasoning and then poured in 3.4 cup of chicken stock.  I cooked until the breast hit 165 then pulled the bird out of the pan, removed the platesetter, and continued to cook the veggies for another 15 minutes because the potatoes weren't done.  Lesson for next time, nuke the potatoes for a couple minutes before putting in the pan with the rest of the veggies.