Heat a sauce pan or deep skillet with a lid over medium heat, add the pistachios and toast for a about 4 minutes or until fragrant. Put the nuts into the bowl of a food processor and let cool.
Return the pan to the heat, add the olive oil and the shallot or onion. Cook for about 3 minutes or until the shallot starts to soften. Add the garlic and quinoa and toast the quinoa for about 3 minutes – you want the quinoa to lightly toast but you do not want the garlic to brown. Add the water and salt and increase the heat to high and bring to a boil. Once the water starts to boil, cover the pan, reduce the heat to medium-low and simmer for about 15 minutes or until all the liquid has been absorbed and the quinoa is tender. Remove from the heat and let sit covered for 5 minutes.
Pulse the pistachios in the food processor until they are roughly chopped. Add the mint and pulse several times until the mint is finely chopped. Stir the mint and pistachios into the quinoa as you fluff it with a fork.