Place half of the thyme into a container and lay the lamb cutlets on top. Cover with the remaining thyme, lemon juice, and half of the olive oil. Make sure all the cutlets are well-coated and covered. Let the lamb cutlets marinate for an hour or two in the refrigerator (or better yet, overnight).
12 lamb cutlets, 3 tbsp. lemon juice, 1 bunch fresh thyme, ½ cup extra-virgin olive oil
Cut the celeriac into medium size chunks, place them in a saucepan with cold water and bring to a boil on high heat. Once the water has reached the boiling point, cover and remove it from the heat, and let sit for about 20 minutes until the celeriac is soft.
1 big celeriac
Drain the celeriac and return it to the pan. Add the pitted black olives and parsley, and season to taste. Then add the remaining olive oil and stir, making sure the celeriac chunks are all well coated.
2 oz. pitted black olives, 2 tbsp. fresh parsley, Sea salt and freshly ground black pepper to taste
Take the lamb cutlets out of the marinade and barbecue or grill for 2 to 3 minutes on each side. (Keep them on the grill more if you like them well done.)
Serve the cutlets on top of the warm celeriac mixture.