Prepare the brown rice noodles according to package instructions until al dente, then drain and set aside.
In a small bowl, whisk together the tamari, fish sauce, rice vinegar, lime juice, and red pepper flakes to create the sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the shrimp to the skillet and cook for 2 minutes per side until pink and opaque, then remove and set aside.
In the same skillet, add the minced garlic and sliced green onions, sautéing for 1 minute until fragrant.
Push the aromatics to the side and crack the egg into the skillet, scrambling it until just set.
Add the cooked noodles, cooked shrimp, and prepared sauce to the skillet, tossing everything together for 2 minutes to coat.
Fold in the bean sprouts and cook for 30 seconds until slightly softened but still crunchy.
Garnish with fresh cilantro and serve immediately.