Chicken: Cut into bite size cubes. Place in a small bowl and mix with spices, until they are lightly coated. Warm olive oil on a frying pan over median heat (10 - 15 min's, turning regularly) until cooked fully.
Grilled veggies: Remove the chicken and set aside. Add a little more olive oil and grill vegetables till soft (5-7 mins).
Crema: Combine avocado, cilantro and lemon juice in a blender or food processor, puree until smooth. Add water (optional) to thin and then season with salt.
Wrap: Create your wrap by layering greek yogurt, crema, grilled vegetables, tomatoes, cilantro and chicken.