Whisk together the yoghurt, herbs, lemon juice, cumin, olive oil, and garlic in a bowl.
Slit the chicken legs at the bone and massage the marinade thoroughly into the meat.
Chill the chicken in the refrigerator for at least 30 minutes or up to 6 hours.
Heat the oven to 200°C.
Sear the marinated chicken skin-side down in a hot griddle pan for 3 minutes per side until marked.
Place the chicken in a roasting tin and bake for 30 minutes until the juices run clear.
Allow the roasted chicken to rest for 10 minutes before carving.
Halve the cucumbers lengthways and remove the seeds with a spoon.
Slice cucumber into wedges and toss with lemon juice, oil, dill, salt, and pepper.
Carve the chicken into eight pieces and serve alongside the cucumber salad.