Preheat the oven to 425 degrees F. Brush a baking sheet with a drop of olive oil or mist it with olive oil. Pat the chicken dry with paper towels.
In a bowl, stir together the lemon zest, salt, pepper, basil, thyme, rosemary, garlic powder and pepper flakes.
Place the chicken on the baking sheet and drizzle it with 1 1/2 tablespoons of the olive oil. Sprinkle the seasoning mixture over top on each chicken thigh. Place the garlic cloves and lemon slices around the chicken. Slice off the top of the garlic head and rub off any excess paper on the outsides, then place the head of garlic, cloves-side up on the sheet too. Take the remaining olive oil and drizzle it over top of the seasoned chicken, head of garlic and lemons.
Roast for 35 to 40 minutes, or until the insides of the chicken reaches 165 degrees F. Remove the chicken and sprinkle on the fresh oregano. Serve!