In a large saucepan or deep skillet, heat the olive oil over medium heat. Add the onion and cook, stirring often, until softened, about 3 minutes. Add the garlic and cook just until fragrant, about 30 seconds. Add the quinoa and cook, stirring, for 1 minute.
Stir in 2 1/4 cups water, season with salt and bring to a boil over high heat. Lower the heat, cover and simmer until the water is absorbed, about 15 minutes. Let stand for 5 minutes. Add the olives, pine nuts, basil, cilantro and parsley and toss with a fork to combine; season with salt.