Add the rice noodles to a pot of boiling water, lower the heat and boil for 3 minutes. The noodles should be softened but still firmer than al dente. They will continue to cook later. Drain and rinse well with cold water. Use kitchen shears to snip the noodles once in half. This will make it a lot easier to fry and eat them.
To make the sauce, stir together the tamarind, brown sugar, and fish sauce until smooth.
Heat a wok over high heat and add about 1 to 2 tablespoons oil (if you’re using a non-stick wok you won’t need a lot). Once the oil begins to shimmer, add the garlic and stir-fry for no longer than a minute (as it tends to burn).
Add the drained noodles and stir for a few seconds. Add the sauce and keep tossing the noodles until they begin to absorb some of the sauce and continue to soften (I use a non-stick wok, but if yours starts to stick, you can add more oil as needed). Add the shrimp and keep stirring until they begin to turn pink, a couple more minutes.
Push the noodles and shrimp to one side (the shrimp will continue to cook so don’t worry if they aren’t completely pink yet) and pour the beaten eggs into the empty space in the wok. Allow the eggs to set for a minute and then stir to scramble it with the rest of the ingredients.
Add the bean sprouts and stir-fry for another minute or two until they are crisp-tender and the noodles have a nice chewy texture. Add half the scallions, toss one final time and remove from the heat.
Divide the Pad Thai evenly over two plates, distributing the shrimp evenly. Garnish with the remaining scallions, chopped peanuts, and lime wedges. Serve immediately.