Firstly, the noodles are to be cooked in a large pot of salted boiling water until they are tender. Then, drain the water.
Mix brown sugar, lime juice, cayenne pepper, fish sauce, and soy sauce in a large bowl and leave it undisturbed.
Take a large non-stick pan and heat oil in it over medium-high heat.
Next, add the bell pepper to the pan and cook for some time.
Add garlic and stir it. Cook for about 1 minute.
Now, add the shrimp. Sprinkle the salt and pepper.
Let it cook per side for about the next two minutes.
Now, keep shrimp and vegetables towards the pan's side and add the egg to the pan.
Stir it well and mix it with shrimp mixture.
Now, add the cooked noodles and toss until they are combined properly.
Following this, add the lime juice mixture and toss again such that the noodles get evenly covered.
Garnish it green onions and roasted peanuts and serve it.