In a mixing bowl, combine soy sauce, mirin, honey, minced garlic, and black pepper. Slowly add water and sesame oil, whisking until smooth.

Bring a large pot of water with white vinegar to a boil. Add baby potatoes and cook for 12–15 minutes until fork-tender. Drain and set aside.

In a skillet, heat vegetable oil over medium heat. Add drained baby potatoes in a single layer and fry for about 4 minutes until golden brown.

Pour the prepared braising liquid over the potatoes, tossing gently. Simmer over medium-low heat for 5–6 minutes until the sauce thickens.

Turn off the heat and sprinkle toasted sesame seeds and green onion. Mix gently and serve warm or at room temperature.