In a bowl, melt 1/4 cup of butter, and then mix in the 1 cup of grated parmesan, 5 cloves of minced garlic, and 2 teaspoons of pepper. Spread this mix on the bottom of your casserole dish.
Wash your baby potatoes and cut them in half. Place them in one layer into the butter spread, with the cut side faced down.
Preheat the oven to 375F.
In a large bowl, mix together the 1.5 tablespoons of dried oregano, 1 tablespoon of paprika, 2 teaspoons of ground black pepper, 2 teaspoons of garlic powder, 1 teaspoon of salt, 1 tablespoon of dijon mustard, and the juice of 1 large lemon. Once mixed, add a layer of this on top of the golden potatoes. You should use just enough to coat them, as you will be using most of the mix for your chicken.
Add the chicken thighs into the seasoning bowl and mix until they are covered in the seasoning. Now add the chicken thighs on top of the potatoes.
Sprinkle the chicken with 2 tablespoons of lemon zest from the lemon you used previously, and with 1/4 cup of grated parmesan.
Cut off the tops of 2 bunches of garlic to expose the garlic. Place the bunches in a sheet of foil. Sprinkle the garlic bunches with salt and drizzle them generously with olive oil. Wrap the foil around them so that they are fully covered and place it onto the casserole dish.
Place in the oven for 50 minutes. After 40 minutes, remove the garlic and open it so it may cool off.
In a bowl, combine 1 cup of yogurt, 1/3 cup of grated cucumber, 1/4 teaspoon of dried dill, 1 tablespoon of lemon juice, and 1/2 tablespoon of olive oil. Squeeze in the roasted garlic and mix well.
Plate the dish by adding several spoon fulls of tzatziki sauce onto a plate. Add the chicken thighs on top and the golden potatoes on the side. Garnish the chicken with a thin slice of lemon and a sprig of parsley.Enjoy!