Let chicken come to room temperature for 20 minutes.
3.5-5 pound whole chicken
Meanwhile, preheat oven to 425° F with a rack in the lower center position of the oven.
In a small bowl, stir together the softened butter, Italian seasoning, garlic powder, salt and pepper. (If the butter is not soft enough to mix well with the other ingredients, you can soften it for a few seconds in the microwave. Just be careful not to melt it.)
4 tablespoons unsalted butter, 1 teaspoon Italian seasoning, 1 teaspoon garlic powder, 1 teaspoon fine sea salt, ¼ teaspoon black pepper
Arrange the onion and carrot in an even layer in the bottom of a large rectangular baking dish, cast iron skillet or roasting pan.
1 yellow onion, 1-2 medium carrots
Remove chicken from packaging. If there is a packet of giblets in the cavity of the chicken, remove it and discard. Pat chicken dry with paper towels. Place the chicken on top of the carrots & onions, breast side up. Tuck the wings under the chicken. Place lemon and a few sprigs of fresh rosemary and/or thyme in the cavity.
½ lemon, a few sprigs fresh herbs
Use a small spoon to loosen the skin from the breasts. Put a spoonful of the butter mixture on each of the chicken breasts, under the skin. Rub your fingers over the skin of the breasts to spread the butter around. Then rub the rest of the seasoned butter over the top of skin on the breasts, thighs and legs.
Use kitchen twine to tie the legs of the chicken together, close to the body of the chicken. (If you don't have kitchen twine, you can skip this step. The chicken may bake 10-15 minutes faster without trussing the legs.)
Pour ¾ cup of water (or chicken broth or white wine) in the bottom of the pan.
¾ cup water, chicken broth or white wine
Bake chicken at 425° F for 65-90 minutes, or until chicken is cooked to an internal temperature of 165° F. (An instant read thermometer inserted into the thickest part of the thigh and breast not touching bone should register at least 165°F. A 3.5 pound chicken will take about 65 minutes, a 4 pound chicken will take about 70 minutes, a 4.5 pound chicken will take about 80 minutes, and a 5 pound chicken will take about 90 minutes. Always confirm doneness with an instant read thermometer.) If the chicken is browning too much as it cooks, you can cover it loosely with foil. Uncovering it during the last 5-10 minutes of cooking will help to make the skin crispy.
Let chicken rest, uncovered, for 15 minutes before slicing and serving.