Place the rice noodles in warm water and set aside to soak for about 30 minutes until they become pliable while you move on to the other steps. Drain when the time is up.
In a small bowl, mix together the tamarind paste, fish sauce, sugar, and lime juice to make the Pad Thai sauce. Adjust the ingredients to taste if needed. Set aside.
Heat the oil in a wok or large skillet over medium-high heat. In a bowl, toss the cubed chicken with the Thai seasoning. Add the chicken to the skillet and cook undisturbed for 2 minutes per side until cooked through (internal temperature 165 ℉).
Add the garlic and stir for about 30 seconds. Push the ingredients in the pan to one side and pour the beaten eggs into the other side. Scramble the eggs until they are just set.
Add the drained rice noodles to the pan and pour the Pad Thai sauce over them. Toss everything together until the noodles are coated with the sauce and heated through.
Stir in half of the bean sprouts and green onions and cook for an additional minute.
Serve the Pad Thai hot, garnished with the remaining bean sprouts, green onions, crushed peanuts, lime wedges, and red pepper flakes if you like it spicy.