To make the marinade, mix 2 teaspoons of Cajun spice with 3 tablespoons of oil and set to one side.
Trim your chicken breasts and then score both sides so to allow flavour to infuse. Place the chicken in a dish and pour the lemon juice over and rub it into the scores. Stir the spice and oil mix and pour over the chicken, again rubbing it into the scores. Cover the chicken and chill in the fridge if not cooking straight away. The longer you leave the chicken to marinate the better (within reason).
Preheat the oven to 150 C / Gas 2.
Remove the chicken from the fridge and transfer to a baking dish along with any marinade and cover with tin foil.
Bake in the centre of the oven for 30 minutes until the chicken is tender and no longer pink in the centre. Remove the chicken from the oven, add some more dry Cajun spice, salt and lots of black pepper and pop into pan with the remainder of the oil and fry on a medium heat for a few minutes to brown further, if desired.
Place the salad and grapes into two bowls and place a chicken breast fillet on top. If you want you can use the oil from the pan as a dressing by adding a splash of balsamic vinegar. Serve.
The aim is to not to overcook the chicken, when done correctly the chicken breast will be juicy. Do not add salt until the very end. I usually add crushed chilli and paprika for extra heat and flavour, oregano also works well.