Cook the rice noodles in boiling water according to package instructions. Drain and set aside, letting them cool slightly.
Season the shrimp with a pinch of salt and set a large skillet or wok over medium-high heat, adding a tablespoon of vegetable oil.
Sauté the shrimp for about 2-3 minutes on each side until they turn pink and are cooked through. Remove from the skillet and set aside.
Add the remaining oil to the skillet and toss in the minced garlic. Cook for about 30 seconds until fragrant and slightly golden.
Pour in the coconut milk, fish sauce, and lime juice, stirring well. Bring the mixture to a gentle simmer, allowing the sauce to thicken slightly and aroma to develop.
Stir in the sugar and red pepper flakes, tasting and adjusting for balance. Let the sauce cook for 2-3 minutes to meld flavors.
Add the cooked noodles into the skillet, gently tossing to coat them in the coconut sauce evenly.
Return the sautéed shrimp to the skillet, placing them on top of the noodles, and allow everything to simmer together for another minute so flavors meld.
Garnish with chopped green onions and a squeeze of fresh lime for brightness before serving.