Cut tofu into 2cm cubes.
Slice the onion and green onion.
Heat oil in a pan and grill the tofu cubes until golden brown on both sides.
Move the grilled tofu aside, then sauté the onion and green onion in the pan.
Make the sauce by combining gochujang, soy sauce, minced garlic, water, and oligosaccharide.
Add the sauce to the tofu and vegetables. Simmer over medium heat.
Turn off the heat when the sauce thickens and becomes reduced.