1. Buy the turkey 3 days before the day you want to cook it.
2. Day 1 - thaw the turkey in the refrigerator, all day.
3. Day 2 - wash the turkey, put it in the oven bag, and put all the marinade inside the oven bag, making sure to get some marinade inside the turkey cavity. Place this oven bag in the refrigerator, with the turkey breast side down.
4. Day 3 - flip the oven bag to marinade the turkey breast side up, and put the bag back in the refrigerators.
5. On the day of cooking, pre-heat your oven to 500F.
6. Remove the turkey from the oven bag and rinse the marinade off the turkey. Throw away the bag.
7. Using a knife point, make 5 slits in the turkey breast, deep enough to put a garlic clove in each slit.
8. Coat the turkey everywhere with garlic-salt, pepper, juice from 1 lemon, and canola oil. Put the rosemary and thyme inside the turkey cavity, along with the big pieces of onion, 1 lemon cut in half, and the remaining 5 garlic cloves. This will serve as the aromatics for the turkey.
9. Put the turkey in a roasting pan breast side up, and place it in the oven on the lowest rack for 30 minutes at 500F. You will see the skin turn brown.
10. Take the turkey out of the oven, and lower the oven temperature to 350F.
11. Cover the turkey breast only with double foil, and put the turkey back into the oven.
12. Let the turkey roast until the breast meat temperature reaches 152F. This should take about 2 to 2-1/2 hours. Dark meat should be more than 160F.
13. Remove from the oven and let the turkey rest for 15 minutes before slicing and serving.