To make the Chicken Seasoning, blend the following ingredients together:
Using a fork, stir the butter until it's a smooth paste and blend in the oil. Stir in the lemon zest and the juice of one lemon.
Toss in the oregano, chopped basil leaves and rosemary.
Stir them in until they are well blended into the butter mixture.
Add the minced garlic cloves and stir the mixture to blend them in.
Next, pour in the white wine and make sure it's thoroughly blended into the butter mixture.
Finally, add the sea salt and the black pepper; stir them into the blend, making sure you combine it well with all parts of the seasonings.
Set this mixture aside while you prepare the meat.
Trim any excess fat from each chicken. Next, remove the plastic bag from inside the cavity of the chicken.
Run cold water over the outside of the bird and thoroughly rinse the cavity.
Use paper towels to pat the birds dry.
At this point, take the blended chicken seasoning and rub it inside the cavity, on top of the skin and under the skin of both birds.
Cover each chicken, separately, in plastic wrap and set them on a tray.
Place the tray in the refrigerator and let the chicken marinate for 1 hour.
While the chickens are marinating in the fridge, it's time to prepare the Balsamic Glaze.
With a spoon, stir until these three ingredients are well-blended together and bring them to a boil.
Once it has come to a boil, reduce the heat to low. Stir this mixture often and let it simmer for 6-8 minutes.
As the water in the vinegar evaporates, the contents will reduce by about 50 percent.
You can tell that it's ready when you insert a spoon into the pan and the back of it is coated with the glaze.
The balsamic glaze will have the consistency of syrup. Remove the pan from the heat and allow it to cool.
Next, preheat the rotisserie grill to medium heat, then remove the chickens from the fridge. Into the cavity of each chicken, place half an onion and half a lemon.
Tuck the wings under the chicken to keep the tips from burning.
Place each bird on the rotisserie spit and place the spit on the grill.
The cooking time will be between one and a half and two hours.
During the last 30-40 minutes, you will need to brush on the balsamic glaze.
It should read 175 F degrees when it's inserted in a few places in each chicken.
Lightly cover each chicken with aluminum foil and let them sit for about 10 minutes.
They will then be ready to carve and serve.