Rinse well the meat under cold running water and pat dry with a kitchen towel. Set aside.
In a small bowl, combine oil with softened butter, lemon juice, lemon zest, salt, thyme, and crushed garlic. Loosen the skin of the chicken from the flesh. Rub this mixture under the skin and the chicken's cavity. Tightly wrap in plastic foil and refrigerate for at least 30 minutes (up to 2 hours).
Preheat the oven to 350 degrees. Line some parchment paper over a baking sheet. Remove the chicken from the refrigerator and remove the foil.
Place onto a baking sheet and roast for 1 hour - 1 hour 15 minutes. Remove from oven and enjoy!