Place the frozen bao buns in a steamer and steam them for 10-12 minutes, until soft and fully heated.
In a small bowl, combine gochujang, soy sauce, apple cider vinegar, maple syrup, minced garlic, paprika, salt, pepper, and ginger (if using).
In a pan over medium heat, add the chicken. Pour the sauce over it, stirring to coat evenly. Cook for 3-5 minutes, until the chicken is heated through and the sauce thickens.
While the chicken is cooking, slice the cucumber and cut the carrot into strips.
Carefully open the steamed bao buns. Fill each with the cooked chicken.
Top the chicken with slices of cucumber and carrot strips.
Garnish with micro leaves and a sprinkle of sesame seeds.