To make MyRecipes.com's Vietnamese Shaking Beef, mix beef with several seasonings, marinate it and combine the other ingredients. After cutting the meat into two equal parts, sear the beef in a large wok or frying pan, add the onions and soy sauce mixture, and repeat the steps with remaining ingredients.
First, trim the excess fat of 1 1/2 pounds of filet mignon and cut the meat into 1-inch cubes. Mix the beef with 1 teaspoon of sugar, 1 tablespoon of oil, and kosher salt and pepper in a bowl. Allow it to marinate for two hours. Stir 1 tablespoon of sugar and soy sauce; 2 tablespoons of rice vinegar and mirin; and 2 teaspoons of dark soy sauce. Add 1/2 teaspoon Vietnamese fish sauce and whip together, ensuring the sugar is fully dissolved.
After heating a large wok or frying pan, heat 3 tablespoons of oil until it shimmers. Place one part of the equally divided beef in a single layer, sear for 30 seconds and cook for another 30 seconds on the other side.
Cook and stir 1/2 cup of thinly sliced red onions and 1 1/2 pieces of green onions cut into 1-inch lengths. Pour in half of the soy sauce mixture and add 1/2 tablespoon of chopped garlic and 1 tablespoon of unsalted butter. Repeat the steps to cook the other half of the beef.