Finely chop the garlic and ginger root. Cut the garlic chives into 1/2" (1.2 cm) pieces. Mix the potato starch with 1 teaspoon of water. Set everything aside.
In a wok, heat oil over medium heat and sauté the garlic and ginger. Add the ground pork and cook for a few minutes until browned. Add the chili paste and cook for an additional minute.
Meanwhile, cook the Harusame in boiling water for 2-3 minutes. Strain well.
Add water, the garlic chives, and the cooked harusame to the wok. Turn the heat down to medium-low and let it simmer for a minute. Season with sugar, salt, sake, and soy sauce. Add the potato starch slurry and stir well until thickened. Finally, stir in the sesame oil.