In a medium bowl, whisk together cornstarch, flour, salt, pepper, and water to form a smooth batter. Add paneer cubes and toss gently to coat.
Heat oil in a nonstick or cast-iron skillet over medium heat.
Working in batches if needed, fry coated paneer until golden brown and crisp on all sides, about 3–4 minutes per side. Transfer to a paper towel–lined plate.
Discard excess oil, leaving about 1 tablespoon in the pan.
Return the pan to medium heat. Add garlic and ginger; sauté until fragrant, about 30 seconds.
Stir in onion and bell pepper; cook until slightly softened, 2–3 minutes.
Add soy sauce, chili sauce, vinegar, sugar, and black pepper. Stir to combine, then add cornstarch slurry. Simmer until sauce thickens and becomes glossy, 1–2 minutes.
Add fried paneer to the sauce and toss to coat evenly. Garnish with green onions if desired.
Serve hot as-is or with fried rice or noodles.
Notes
Cooking Tips
For extra crispy paneer, chill coated paneer cubes in the fridge for 10 minutes before frying.
Prefer more crunch? Double-fry the paneer or increase cornstarch slightly.
Keep vegetables slightly crisp to balance the creamy paneer and thick sauce.
Adjust heat by increasing or decreasing chili sauce.
Storage & Reheating
Storage: Store in an airtight container in the refrigerator for up to 2 days.
Reheating: Warm in a pan over low heat with a splash of water to prevent the sauce from drying out.