Cut the soft tofu into bite-sized pieces.
Slice the green onions and red chili pepper finely.
Heat cooking oil in a pan and sauté minced garlic.
Mix soy sauce, water, oligosaccharide, and pepper to make the marinade.
Add the soft tofu to the marinade and simmer over low heat.
When the sauce thickens, top with green onions and red chili pepper to finish.