Place the dry brown rice noodles in a large bowl and cover with very hot water, soaking for 15-20 minutes until flexible but still firm.
In a small jar, whisk together the tamarind paste, coconut aminos, and fish sauce to create the Pad Thai sauce base.
Heat the avocado oil in a large wok or non-stick skillet over medium-high heat.
Add the minced garlic and red pepper flakes, sautéing for 30 seconds until fragrant.
Add the shrimp to the pan and cook for 2 minutes per side until pink and opaque, then push them to one side of the wok.
Crack the egg into the empty side of the wok and scramble quickly until just set.
Drain the noodles and add them to the wok along with the prepared sauce, tossing vigorously for 1-2 minutes until the noodles absorb the liquid.
Fold in the bean sprouts and sliced green onions, cooking for only 30 seconds to maintain their crisp texture.
Transfer to a plate and garnish with crushed peanuts and a fresh squeeze of lime juice before serving.