Add cooking oil to a skillet, and heat on low-medium heat.
Carefully chop the celery and mince the green bell peppers.
Transfer the veggies to the skillet, and season with salt and pepper.
Sauté on medium heat for a few minutes, keeping an eye on the veggies.
Remove from the skillet and set aside.
Using a mixing bowl and your hands, combine the ground meat well.
Drizzle cooking oil in the same skillet, and add the ground meat.
Using a potato masher, mash the meat into very tiny pieces.
Cook until browned, which should only take a few minutes.
Immediately add the beef broth, cornstarch, and flour. Whisk well.
Put the veggies back in the skillet and follow by adding the other spices.
Then add the milk, white vinegar, and sugar.
Bring to a boil.
Reduce the heat and let the mixture simmer for about half an hour.