Heat a large pan or wok to medium heat and add chili oil.
Add potatoes and cook about 5 minutes to soften.
Add onions and peppers and cook another 5 minutes, or until onion is cooked through. Set potatoes, peppers and onions aside.
Add shrimp and sprinkle with salt, pepper and chili powder. Cook about 4 minutes, or until shrimp is cooked through. Set shrimp aside with potato/pepper/onion mixture.
To the hot pan, add chili paste and cook about 3 minutes.
Add beer and bring to a boil. Allow to reduce by about half.
Add coconut milk, chicken broth and noodles. Stir. Cook about 10 minutes, or until noodles absorb the liquids and get nice and soft to your preference.
Return potatoes, peppers, onions and shrimp to the pan and stir. Heat to warm everything together.
Remove from heat. Season with salt and pepper, then stir in brown sugar, lime juice and fish sauce.
Serve to bowls and top with cilantro.