Add potatoes and carrots to a roasting pan. Spray with a little olive oil spray and sprinkle a bit of salt on top. Add the rack on top of the veggies.
Place the onion and lemon inside the cavity. Tuck the wings underneath then tie the legs with a piece of twine.
In a small bowl, mix together the softened butter, rosemary, thyme, and coarse salt. Lift the skin off the breast of the chicken and place the butter mixture underneath the skin on each breast, then use your fingers to spread it evenly throughout. Place the chicken on the roasting rack breast side up.
In another small bowl, whisk together olive oil, salt, paprika, and garlic powder. Use a basting brush to baste the chicken with 1/2 the olive oil mixture.
Place in the oven to roast for 35 minutes then baste the chicken once more and roast for 35 more minutes. Turn temperature up to 425 degrees F and roast for another 10 minutes. Remove from oven and let rest for at least 10 minutes before slicing and serving. Serve the chicken with potatoes and carrots, and enjoy every juicy bite!