Stir-fried Shredded Beef With Fish-flavored Shrimp

• 4 water chestnuts
• 1 cornstarch
• 1 pepper powder
• 700 ml oil
• 230 gr beef
• 16 ml dark vinegar
• 16 gr ginger
• 16 ml soy sauce
• 9 gr chili nam yuey
• 8 gr garlic