Cut the chicken breast into bite-sized pieces.
Slice the onion, green onion, shiitake mushrooms, and tofu into easy-to-eat sizes.
Put soy sauce, cooking wine, water, and stevia into a pan and bring to a boil.
Once the broth is boiling, add the chicken breast, vegetables, and tofu.
Simmer over medium heat until all ingredients are cooked.
Adjust the seasoning to taste before serving.