Preheat the oven to 350°. On a work surface, mince the garlic with 1 teaspoon of kosher salt. Transfer the garlic to a small bowl and whisk in the lemon juice, rosemary, sweet paprika, cumin, hot paprika and 1/2 teaspoon pepper. Whisk in the olive oil.
Using your fingers, gently loosen the skin from the chicken breasts, thighs and drumsticks; try not to tear the skin. Season the cavity of the chicken with salt and pepper and put the chicken in a roasting pan. Using a small spoon, pour all but 1 tablespoon of the seasoning mixture under the skin of the chicken, rubbing it into the breasts, thighs and drumsticks. Rub the butter under the skin of the breast meat. Rub the remaining 1 tablespoon of the seasoned oil all over the chicken and season it with salt. Put the reserved lemon halves in the cavity of the chicken and tie the legs together with twine.
Roast the chicken for about 1 1/2 hours, or until the juices from the cavity run clear and the chicken is browned and crisp. Let the chicken rest in the roasting pan for 15 minutes.
Tilt the chicken to drain the juices from the cavity into the pan; transfer the chicken to a carving board. Pour the pan juices into a bowl and skim the fat from the surface. Strain the juices into a small saucepan and keep warm over low heat. Carve the chicken and serve with the pan juices.
The rich fruitiness of a good cru Beaujolais would provide a bright contrast to the chicken's crispy skin.