Toss cubed paneer with cornstarch and a pinch of salt to coat evenly.
Deep-fry paneer cubes in hot oil until edges are crisp and golden; set aside.
Heat 1 tbsp oil in a wok, stir-fry garlic paste, slit green chilies, cubed onion, and capsicum for 2 minutes.
Add soy sauce, vinegar, and salt; stir well.
Toss fried paneer into sauce on high flame for 1 minute until glazed, then serve hot.