In a small bowl, combine the olive oil, black pepper, Moroccan spice mix, ginger and garlic to create a paste. Rub paste all over chicken fillets and refrigerate for 30 minutes - 2 hours.
Preheat oven to 180C
In an oven proof frying pan, heat 1 tablespoon of oil on a medium heat and sear chicken, about a minute each side or until lightly browned. Place in oven and roast for 15-20 minutes, until just cooked. Remove and set aside to cool.
For the dressing, whisk together the mayonnaise, mustard and lemon juice in a bowl.