Cut potatoes into thin finger strips, toss with cornstarch and salt to coat evenly.
Deep-fry potato strips in hot oil until golden brown and very crisp; drain on paper towels.
Heat 1 tbsp oil in a wok, sauté garlic paste, chopped green chili, and sesame seeds.
Add soy sauce, 1 tbsp water mixed with 1 tsp cornstarch, and stir until glossy.
Turn off heat, toss in fried potato finger strips until coated, and garnish with spring onions.