Steam the tempeh for about 10-15 minutes, then transfer it to a mixing bowl. Mash tempeh with a fork, then add minced garlic, egg, oyster sauce, worcestershire sauce, cornstarch, salt, chicken stock powder, nutmeg, and black pepper. Stir until well combined.
Shape the tempeh mixture into slightly flattened round patties, then grill on pan fry over medium heat until both sides are golden brown.
In the same pan, saute garlic and onion over medium heat until fragrant. Add tomato sauce, chili sauce, bbq sauce, oyster sauce, and water, stir until well combined. Once the sauce mixture boiling, add black pepper, salt, and mushroom seasoning. Stir well.
Dissolve cornstarch in a water then add in into a sauce mixture, stir and cook until the sauce is thickens slighlty.
Serve the tempeh steak into a plate. Pour the sauce on top of the tempeh steak. You can also serve it with steamed vegetables and mashed potato. Enjoy!