Soak rice noodles in very hot water for 20-30 minutes until limp but firm, then drain.
In a small bowl, whisk together tamarind paste, fish sauce, brown sugar, and chili flakes to create the sauce.
Heat vegetable oil in a wok or large skillet over high heat.
Add chicken slices and stir-fry until cooked through and slightly browned.
Push chicken to the side of the pan and pour in the beaten eggs, scrambling them until just set.
Add minced garlic and stir for 30 seconds until fragrant.
Add the drained noodles and the prepared sauce to the pan.
Toss continuously for 2-3 minutes until the noodles absorb the sauce and become tender.
Fold in the bean sprouts and green onions, cooking for an additional 1 minute.
Remove from heat and serve immediately topped with crushed peanuts and lime wedges.