1) If using brown rice noodles, boil in water per package cooking instructions until al dente. If using white rice noodles, place in a large bowl of hot water to cover. Let soak until tender but not mushy, about 5 -10 minutes. Drain and set aside.
2) While noodles are cooking or soaking, prepare the sauce by mixing tamarind paste with water, tomato paste, fish sauce, maple syrup, chili flakes or diced chili peppers, and shrimp paste (optional) together and mix well. Set aside.
3) Spread a tsp of oil (or nonstick cooking spray) in a wok or large skillet over medium-high heat. Add whisked eggs and scramble until just done. Set aside and cover.
4) If adding shrimp, pork, chicken or tofu, use the same pan and add a tablespoon of oil to the pan. When the oil is hot, add shrimp, pork, chicken, or tofu and garlic. Stir until shrimp or other meat is cooked through. Set aside with eggs and cover.
5) Add a tablespoon of oil. When the oil is hot add snap peas or green beans (or any thicker vegetable) and cook until just shy of completion, with a few more minutes cooking time remaining. Add the quick cooking vegetables (like shredded carrots and sliced red peppers) and cook for another minute.
6) Add noodles and cook for 1 minute. Stir in sprouts, scrambled eggs, and shrimp (or pork, chicken, or tofu). Add sauce and cook while stirring until sauce is absorbed into the noodles and noodles are well coated, about 1 minute. Stir in Thai chilies (optional), about half the peanuts, and toss well. Transfer to the serving plates and garnish with chilies, chopped peanuts, cilantro and lime wedges.
7) Stir in Thai chilies (optional), about half the peanuts, and toss well. Transfer to the serving plates and garnish with chilies, chopped peanuts, cilantro, and lime wedges.