Rinse quinoa in a bowl with water or place quinoa in a fine mesh sieve and rinse under cold water until water runs clear. Transfer to a saucepan and add a healthy pinch of sea salt and 1 ¾ cups water. Bring to a boil, cover, and lower to a simmer. Cook until water is absorbed, about 15 minutes. Turn off the heat and allow to sit covered for 10 minutes.
Transfer quinoa to a serving bowl and allow to cool. Fluff with a fork periodically.
Whisk the olive oil, lemon juice, lemon zest, salt and oregano together in a jar or small bowl.
Combine cooled quinoa, dressing and remaining ingredients and toss to mix well. Taste for seasoning.