Brown the Beef : In a large skillet or wok, cook the lean ground beef over medium heat until browned and fully cooked. Drain any excess fat, if needed, and set the beef aside.

Prepare the Base : In the same skillet, add 1 1/2 cups of water, soy sauce, and the beef bouillon cube. Stir well to dissolve the bouillon cube completely. Bring the mixture to a gentle simmer.

Cook the Vegetables : Add the chopped celery and thinly sliced onion to the skillet. Cook for 5–7 minutes, stirring occasionally, until the vegetables are tender-crisp.

Add the Sprouts and Water Chestnuts : Stir in the drained bean sprouts and water chestnuts. Cook for another 2–3 minutes, allowing the vegetables to heat through and absorb the flavors of the sauce.

Thicken the Sauce : In a small bowl, mix the cornstarch with 2 tablespoons of water to create a slurry. Gradually add the slurry to the skillet while stirring continuously. Cook for 2–3 minutes until the sauce thickens and evenly coats the beef and vegetables.

Combine and Serve : Return the cooked ground beef to the skillet and stir well to combine with the sauce and vegetables. Cook for another minute to ensure everything is heated through. Serve the chow mein over steamed rice, noodles, or as-is for a lighter option.