In a medium bowl, combine soy sauce, oyster sauce, fish sauce, sugar and black pepper. Mix until well combined. Place beef in another medium bowl. Add half the marinade and toss to coat. Marinate ...
If mixture looks too tight, loosen with splashes of hot water. Season with salt to taste. To serve, ladle upma into bowls and garnish with dollops of yogurt, chopped cilantro and lime juice.