At least 2 hours before cooking, mix the chilli, garlic, the juice of half a lemon, 2 tbsp of the oil and a splash of water together. Coat the chicken with the mixture, cover in cling film and refrigerate.
About 25 minutes before eating, slice the radishes thinly. Then dissolve the sugar and a pinch of salt in the vinegar by heating it in small saucepan. Pour the mixture over the radishes and set aside.
Next cut the cucumber in half and scoop out the middle. Coarsely grate it into a bowl. Mix in the rest of the lemon juice, the yoghurt and a pinch of salt.
Finally heat a griddle pan over a high heat and add the remaining oil. Once the oil is sizzling add the chicken and cook for about 7 minutes on each side (this depends on how thick the chicken is.)
Scoop the yoghurt onto a plate, place the chicken on top and sprinkle over the pickled radishes.