Heat the oil in a large skillet or wok over medium heat.
Add the diced onion and cook for 3 to 5 minutes, until it becomes soft and translucent.
Add the minced garlic, ginger, daikon radish, sweet potato, carrots, bell peppers, and tofu to the skillet.
Cook for 5 minutes, stirring frequently to prevent sticking.
Pour in the teriyaki sauce and stir to coat everything evenly.
Bring the sauce to a gentle simmer, then cover the skillet, reduce the heat to low, and cook for an additional 3 minutes, or until the vegetables are tender-crisp.
Remove from heat.
Taste and adjust seasoning if necessary.
Garnish with fresh cilantro or parsley and serve immediately.