Prior to cooking, coat chicken in dry rub and wrap tightly with plastic wrap. Refrigerate at least one hour or overnight.To cook over a campfire:
To prepare for cooking, heat 24 coals. Place 8 of the hot coals evenly under dutch oven.
When the cast iron is hot, add the butter and melt. Sear the breast side of the chicken for about 5 minutes in the hot butter.
Remove the chicken and spread the vegetables in the pot.
Then return the chicken to the pot, breast side up with the meat thermometer inserted into the thickest part of the breast. You may need to redistribute the vegetables to get the chicken to fit. Ideally you want the chicken in the middle of the dutch oven and not touching the lid or the base.
Cover with the lid and add remaining 16 coals to the lid. Rotate the lid a quarter turn every fifteen minutes or so. After about 45 minutes of cooking, you may need to add a few more hot coals. Just be sure to add twice as many to the top as you do the bottom. Continue cooking until the internal temp reads 165 degrees F and the drumsticks start to pull away from the body. This may take 1-1.5 hours. Cooking time may be shorter with two smaller chickens.
To cook in your oven:
Preheat oven to 350 degrees F with the dutch oven inside the oven. You want it to get hot.
When the cast iron is hot, add the butter and melt. Add the chicken to the dutch oven, breast side down, and cook in oven for about 5 minutes in the hot butter.