Clean and rinse shrimp. Pat dry with paper towels and set aside. Add cornstarch, salt and red pepper flake, tossing to coat.
Prepare sauce: rice wine vinegar, pineapple juice, pineapple tidbits, fish sauce, lemon juice and pepper.
Heat a skillet to medium heat and add butter. Once butter is melted add minced garlic sautéing until fragrant, about one minute.