Most of the pots are not hot enough ~ I suggest that you burn the pot with strong fire until the face is close to 15-20 cm, then add oil and turn to medium heat (remember to raise your face ...). After about 20-30 seconds, stir-fry the meat for about 6 minutes, and then turn to high fire to stir-fry it quickly (if you are afraid of being undercooked, you can also throw it again). Remember to stir fry quickly under the green pepper and pour in the sauce. Don't make the green pepper too soft, it will be delicious.