Combine the first 7 ingredients in a bowl. Preheat your grill to medium-high. Grill the chicken 3 to 4 minutes per side, or until cooked through. Set the chicken on a plate and cool a few minutes. Set each tortilla on a dinner plate. Spread the centre of each tortilla with sour cream. Top it with the lettuce, avocado and salsa. Slice the chicken and set an equal amount of it, and the cheese, on each tortilla. Allow diners to fold and roll their tortilla into a cone shape and then devour.