In a bowl, combine soy sauce, sesame oil, ginger, garlic, salt, and pepper.
Add chicken thighs to the marinade and let sit for at least 15 minutes.
Preheat a grill or grill pan over medium-high heat.
Remove chicken from marinade and discard the leftover marinade.
Place chicken on the grill and cook for 6-7 minutes per side.
While chicken cooks, slice your vegetables into bite-sized pieces.
In a separate pan, heat vegetable oil over medium heat.
Add vegetables and stir-fry for about 5-7 minutes until tender.
Once chicken is cooked through, let it rest for a few minutes before slicing.
Serve the chicken with the stir-fried vegetables and lemon wedges.