In a large bowl, mix together the chicken, the juice of 1 lemon, 250ml yogurt, the jerk paste, red onion and half the coriander. Allow to marinate for 10-15 minutes.
Preheat the grill to medium-high. Meanwhile, thread the chicken and red onion on to the skewers with a few of the lemon wedges. Put under the grill for 10-15 minutes, turning halfway through, until golden and cooked through.
Meanwhile, mix together the remaining yogurt, the mixed vegetable stir-fry, wholegrain mustard, carrots and the remaining lemon juice. Season with freshly ground black pepper. Warm the tortillas through in the microwave or under the grill for 1 minute.
Serve the skewers with the tortillas and slaw, then garnish with a sprinkling of coriander.