Prepare and Marinate the Beef: Trim excess fat from the fresh beef and cut it into thin strips. In a bowl, marinate the beef strips with soy sauce and ground pepper according to taste. Set aside and let it marinate for at least 15-20 minutes.

Prepare Vegetables: Rinse the bean sprouts and drain. If using canned button mushrooms, drain them well.

Make Molasses Paste: In a small bowl, mix molasses powder with a small amount of water to form a paste. Set aside.

Heat Shortening: In a large wok or skillet, heat the shortening over medium-high heat.

Stir-Fry Beef: Stir-fry the marinated beef in the hot shortening until browned and cooked through. Remove beef from the wok and set aside.

Prepare Sauce: In the same wok, add the diced red onion, chestnuts, and sliced celery. Stir-fry until vegetables are tender.

Add Molasses Paste: Add the molasses paste to the vegetables, stirring to combine. This will add a sweet and savory flavor to the dish.

Combine: Return the cooked beef to the wok and add the canned button mushrooms. Stir everything together.

Season: Season the mixture with sea salt according to taste. Adjust the seasoning as needed.

Add Bean Sprouts: Toss in the fresh bean sprouts and cook briefly until they are just tender. Be careful not to overcook, as you want to retain their crispiness.

Garnish and Serve: Garnish the Old Fashioned Beef Chop Suey with soy sauce according to taste. Serve over cooked noodles (chow mein) or rice.

Enjoy: Serve the delicious Old Fashioned Beef Chop Suey hot, savoring the flavorful combination of tender beef, crisp vegetables, and the rich molasses-infused sauce.