Soak the rice noodles in warm water for 20-30 minutes, or until they are soft and pliable.
Heat a wok or large frying pan over high heat. Add the vegetable oil and swirl to coat the pan.
Add the garlic and shallot and stir-fry for 1-2 minutes, or until fragrant and starting to brown.
Add the shrimp and stir-fry for 1-2 minutes, or until they are pink and cooked through.
Push the shrimp and vegetables to the side of the pan and add the beaten eggs to the center. Scramble the eggs until they are fully cooked.
Add the drained noodles to the pan and toss everything together.
In a small bowl, whisk together the fish sauce, tamarind paste, palm sugar, soy sauce, and chili flakes (if using). Pour the sauce over the noodles and toss until the noodles are fully coated.
Add the bean sprouts and continue to stir-fry for 1-2 minutes, or until the noodles are cooked to your desired level of doneness.
Remove the pan from the heat and stir in the chopped peanuts and cilantro.
Serve the pad Thai hot, garnished with additional chopped peanuts, cilantro, and lime wedges.