1. If you’re starting with raw chicken breasts, poach it in a couple of inches of simmering water for about 10 minutes. Slice into it to check that it’s cooked through. If you’re using leftovers or rotisserie chicken, cut into 1-inch cubes.
2. In large bowl, mash avocado, add the rest of your ingredients and combine well. Taste and check seasoning.
3. Lay out tortilla on a work surface. Scoop 1/2 cup of chicken salad onto it and spread evenly right to the edge. Roll snugly. Use serrated knife to slice tortilla rolls into pinwheels. This will be easier to do if you chill the rolls first.