Black Pepper Beef Udon

Name: Black Pepper Beef Udon
Prep time: 5 min
Cook time: 10 min
Total time: 15 min
Cuisine: Asian
Ingredients: 200 g or single serve packet of fresh udon; 100 grams of shabu shabu beef; 1/2 onion; 1 tsp garlic, minced; 1/2 tsp ginger, minced (optional); 1/4 cup dark soy sauce (or kicap manis); 1 tsp oyster sauce; 1 tbsp tomato paste; 2 tsps black pepper (adjust to preference); 1 cup water; a handful of chye sim (or any leafy greens); cornstarch slurry of 2 tsps cornstarch + water