Cook the egg noodles or udon noodles, drain and keep aside.
Heat butter in a pan.
Add minced garlic to the pan and saute for a few minutes until aroma comes.
Add prawns, salt and pepper to the pan. Cook this for a few minutes on high flame until they cooked well. Remove the prawns from the pan and keep them aside.
In the same pan, add sliced bell pepper and zucchini. Saute for a few minutes until all vegetables turn soft and crispy.
In a small bowl, add soy sauce, oyster sauce, fish sauce and red pepper flakes. Stir all ingredients together until mixed well. keep the sauce aside.
Add cooked noodles and the sauce mixture into it. Mix well in the sauce until coated with noodles and vegetables evenly.
Add cooked prawns to the pan and mix everything together. Cook this for a few minutes.
Remove the pan from heat and finally, garnish the garlic butter prawn noodles with chopped fresh coriander leaves.
Garlic butter prawn noodles are ready to serve.