Flatten the chicken thighs between two sheets of baking paper until about 1/2 cm thick. Season with salt and pepper, then heat a tablespoon of vegetable oil in a skillet over medium-high heat. Cook the chicken for 5-6 minutes on each side, or until golden brown and fully cooked. Let it cool for a few minutes before shredding it into bite-sized pieces.

Bring a pot of water to a boil, then add the rice vermicelli noodles. Let them soak for 5 minutes until tender, stirring occasionally. After soaking, drain the noodles and rinse them under cold water to prevent sticking. Set the noodles aside in a bowl, ready for assembly.

While the noodles are soaking, wash and julienne the carrot and cucumber. Chop the spring onion, and slice the red chilli if using. Gather fresh coriander leaves and set these vibrant ingredients aside.

Fill a shallow dish with warm water. Take a rice paper wrapper and dip it into the water for about 10-15 seconds until it becomes soft but not overly soggy. Lay the softened wrapper flat on a clean cutting board or plate.

Place a small amount of noodles, shredded chicken, julienned carrot, cucumber, spring onion, red chilli, and coriander in the middle third of the softened rice paper. Be careful not to overfill. Fold the bottom edge over the filling, tuck in the sides, and roll tightly to enclose the filling.

Arrange the finished summer rolls on a serving platter. Serve them with your choice of hoisin or chili sauce on the side for dipping.