In a large pot, brown chicken with oil in batches until fully cooked and transfer to a plate.
Add curry paste to pot and cook it for about 30 seconds, stirring continuously. Pour in stock and coconut milk, and bring to a boil. Reduce and simmer uncovered 10 minutes. Add shrimp and simmer another 3-5 minutes or until shrimp are fully cooked. Add reserved chicken.
In another pot, boil noodles until tender. Drain, rinse and divide among 4-6 bowls. Divide garnishes among bowls then pour over hot soup (dividing up chicken and shrimp). Salt to taste.
Notes
For vegetarian, omit the chicken and shrimp or replace with diced firm tofu.