Cook the Noodles:
Cook the rice noodles according to the package instructions. Drain and set aside. You can toss the noodles with a small amount of oil to prevent them from sticking together.

Make the Broth:
In a large pot, heat a little oil over medium heat. Add the minced ginger and garlic, sautéing for about 1 minute until fragrant. Stir in the red curry paste, cooking for another minute. Pour in the chicken or vegetable broth, coconut milk, soy sauce, fish sauce, brown sugar, and chili flakes. Stir well to combine.

Add Lemongrass and Simmer:
Add the smashed lemongrass stalks (or lemongrass paste) into the pot. Bring the soup to a gentle simmer over medium heat. Let it simmer for about 10 minutes to allow the flavors to infuse.

Cook the Shrimp:
After the broth has simmered, add the shrimp to the pot and cook for 3-5 minutes, or until the shrimp turn pink and are fully cooked.

Assemble the Soup:
Remove the lemongrass stalks from the soup and discard them. Add the lime juice to the broth and taste for seasoning, adjusting with more soy sauce, fish sauce, or chili flakes if desired.

Serve:
To serve, divide the cooked rice noodles among bowls. Ladle the hot shrimp and broth mixture over the noodles. Garnish with fresh cilantro, green onions, and sliced red bell pepper for a burst of color and flavor.