mapo tofu recipe

2/3 cup low sodium chicken broth (or water) ▢1 pound silken tofu (cut into 1 inch/2.5cm cubes) ▢1/4 cup water ▢1 1/2 teaspoons cornstarch ▢1/4 teaspoon sesame oil (optional) ▢1/4 teaspoon sugar (optional) ▢1 scallion (finely chopped)