Heat your oven to 400ºF and set out a large sheet pan. Add the chicken and potatoes onto the sheet pan and set aside.
Using a vegetable peeler, remove the zest from the lemon then thinly slice. Add the lemon zest, salt, garlic, oregano, coriander, red pepper flakes, and oil to a mortar and pestle or to a small blender or food processor and blitz into a paste. Add the paste onto the chicken and potatoes and toss to evenly coat. Arrange in an even layer and so that the chicken so that it is skin-side up and roast until the potatoes are tender and golden and the chicken is cooked through, 35 to 45 minutes, depending on how large the chicken thighs are.
Remove the potatoes to a serving dish and top with the chicken. Squeeze the lemon onto the sheet pan and stir to scrape up any stuck-on bits. Pour the lemon juice over the chicken and potatoes.
Crumble the feta over the chicken and potatoes and scatter with the herbs and olives. Serve with lemon wedges on the side.