Preheat oven to 450F. Spread the oil in the bottom of your dutch oven. If you use an oil sprayer, spray the sides as well.
Place the onions in the bottom of the dutch oven and spread them out to cover the bottom.
Add baby carrots over the onions.
Spritz the veggies with oil and sprinkle the vegetable seasonings over the carrots and onions.
Add the potatoes on top.
Place the whole chicken over the potatoes.
Squeeze the lemon by hand over the chicken (try to pick out any seeds before squeezing), and place the squeezed lemon halves in the pot next to the chicken.
Spritz the chicken with oil
Sprinkle the seasoning over the chicken.
Place the rosemary sprigs on top of the chicken if using. Place the dutch oven in the preheat oven WITHOUT its lid, and cook for 20 minutes.
Remove the pot from the oven and place the lid on the dutch oven. If the bottom of the dutch oven seems dried out, you can add a bit more oil or even chicken broth. Just enough to keep the bottom from drying out.Reduce the oven heat to 350F. and place the dutch oven back into the oven.Cook for approximately 1 hour 10 minutes (or until the chicken reaches at least 165F. on a meat thermometer)
Remove the dutch oven from the oven and carefully remove the lid. There will be steam, so slide the lid towards you first so the steam can escape out the back instead of burning you. (personal experience talking!) Serve with the veggies and maybe a side of rice!
Please note that the nutrition data below is a ballpark figure. Exact data is not possible.