Place the chicken breasts, one at a time, between 2 sheets of clingfilm and, using a kitchen mallet or rolling pin, pound to an even thickness of about 1.5 cm. Brush the chicken breasts all over with the tandoori spice paste.
Heat a grill pan until very hot. Brush it with olive oil and add the chicken breasts. Cook for 2–3 minutes on each side or until cooked t