Rinse the quinoa under cool running water, then drain well with a fine-mesh sieve or cheesecloth-lined strainer (the grains are very small and will slip through a coarse strainer).
Heat a wok over medium-high heat and toast the quinoa, shaking the pan frequently, just until the grains dry, are just beginning to color and have a nutty aroma, 3 to 5 minutes. Set aside in a bowl.
In a medium, lidded pot, bring 1 quart of water to a boil over high heat.
Stir in the quinoa with a pinch of salt, then reduce the heat to a simmer and cover.
Cook the quinoa until the grains are translucent and tender and the germ has spiraled out from the grain, about 15 minutes (do not overcook).
Remove from heat, drain and set aside.
Meanwhile, heat the wok again over high heat.
Add oil and heat until it just begins to simmer.
Add the garlic and fry, stirring constantly, just until the garlic is golden, 25 to 30 seconds (the garlic can burn quickly).
Remove the garlic with a slotted spoon, keeping the oil in the pan, and set aside.
Stir in the fennel to the oil and fry, stirring or tossing frequently, until it is caramelized, about 6 minutes.
Remove from the oil and set aside.
Stir in the shiitakes to the oil and stir-fry until caramelized, about 6 minutes.
Add the green onions in with the mushrooms and continue to stir-fry just until the green onions begin to wilt, about 2 minutes.
Stir in the soy sauce and vinegar to the mixture and stir or toss to combine, then remove from heat.
In a large bowl, gently toss the quinoa with the warm mushroom-green onion mixture, the fennel, garlic, cashews, parsley, cilantro, lime zest and juice.
Season with salt if needed and serve immediately.
