Cut the mushrooms and beef into bite-sized pieces.
Julienne the onion and carrot.
Heat cooking oil in a pan and stir-fry the onion and carrot.
Add the beef and stir-fry. When it's about half cooked, add the mushrooms.
Add soy sauce, minced garlic, pepper, and water. Cover with a lid and steam over medium heat.
When all the ingredients are cooked through, turn off the heat and plate the dish.