In a mixing bowl, combine the chopped carrots, cabbage, bell pepper, mushrooms, soy sauce, sesame oil, ginger, and garlic. Mix well.

Let the mixture sit for about 10 minutes to allow the flavors to meld.

Soak one rice paper sheet in warm water for about 10 seconds until soft.

Place a spoonful of the vegetable filling in the center of the rice paper.

Fold the sides over the filling and roll tightly to form a dumpling. Repeat with remaining rice paper and filling.

Place the dumplings in a steamer lined with parchment paper to prevent sticking.

Steam for about 10-12 minutes until the rice paper is translucent and the filling is heated through.

In a small bowl, mix together soy sauce, rice vinegar, sugar, and chili sauce if using. Stir until sugar is dissolved.

Serve the steamed dumplings hot with the dipping sauce on the side.