Place the chicken thighs on a small baking sheet. Brush the teriyaki sauce all over the chicken. Bake in the oven for 20-25 minutes until cooked through. Remove the chicken from the oven. Allow to cool. Slice the chicken into thin strips.
In the meantime, add the red pepper and cabbage to a bowl. Add the sugar, rice vinegar and salt and toss to combine.
Arrange all the ingredients so they are at the ready.
Add some tepid water to a pie plate or a shallow plate with a rim, large enough to accommodate the rice paper roll.
Slide one rice paper sheet into the water until fully submerged. Keep it in the water for no more than 6-8 seconds. It will still be a little rigid but it will soften as you begin to add the other ingredients. Place the rice paper on a work surface. At the edge closest to you, in the bottom third of the rice paper, add a couple leaves of mint and cilantro. Top with a few slices of mango, some cucumber, some cabbage and red peppers and top with a few slices of chicken. Fold the bottom edge over the fillings, tuck, fold in the sides and roll tightly. Continue with the remaining rice paper sheets.
Cut each roll in half ( or can serve whole) and serve with the chili sauce.
