Start by cutting the beef into thin strips then transfer all this meat to a medium bowl.
Season with the salt, the soy sauce, the black pepper and mix.
Add the egg and mix again.
Next, add the cornstarch, mix until the starch dissolves and set aside.
In a large skillet over medium to low heat, add a drizzle of olive oil.
Add the meat we prepared earlier, fry until golden brown then remove it from the skillet.
In the same skillet, add another drizzle of olive oil, the red bell pepper cut into strips and sauté until slightly wilted.
Add the onion cut into thin strips and sauté until golden brown.
Next, add the meat again and stir until combined.
Add the soy sauce, the alcohol vinegar and stir.
Now, add the sugar, the cornstarch dissolved in the water and keep stirring for another minute.
Add the crushed garlic cloves, the red chili pepper chopped into small cubes and stir for another 5 minutes.
Transfer to a plate and finish by adding parsley to taste.
Serve.