Meanwhile, make the poultry seasoning. Mix all the ingredients together in a small dish.
Quarter the potatoes and onion and cut the carrots into 3 inch pieces. Mince the garlic. Slice the lemon.
Pat the chicken dry. Season lightly on the inside and outside of the chicken with salt and pepper. Use your hands to spread the ghee all over the chicken skin and under the breast skin (this is the key to crispy chicken skin). Put half of the lemon, half of the garlic, and half of the onion inside the chicken cavity. Sprinkle heavily with the poultry seasoning. Optionally, you can truss the chicken.
Spray or lightly oil the bottom and sides of the inside of the dutch oven. Add the resto of the vegetables to the bottom of the dutch oven, then set the chicken on top of the vegetables. The chicken should sit off the bottom of the dutch oven, but not so high that you can't put the lid on.
Cover and bake for one hour. Remove the lid and cook with the lid off for another 30-35 minutes. If you like the skin a little extra crispy, turn on the broiler and broil the chicken for about 2 minutes.
Remove the dutch oven from the oven and allow the chicken to rest for at least 10 minutes. Serve immediately.