Soak the rice noodles in a bowl of very hot water for 20-30 minutes until flexible but still firm (al dente), then drain and set aside.
In a small bowl, whisk together the tamarind paste, fish sauce, and coconut aminos 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 shrimp and cook for 1-2 minutes per side until pink and opaque. Remove shrimp from the pan and set aside.
In the same pan, add the minced garlic and white parts of the sliced green onions, sautéing for 30 seconds until fragrant.
Push the aromatics to the side of the pan and crack the egg into the center. Scramble the egg quickly until just set.
Add the drained noodles and the prepared sauce to the pan. Toss vigorously for 2-3 minutes using tongs until the noodles absorb the sauce and soften.
Fold in the cooked shrimp, bean sprouts, and the green parts of the green onions. Toss for another minute until the sprouts just begin to wilt.
Serve immediately topped with crushed peanuts, red pepper flakes, and a fresh squeeze of lime juice.