Bring a medium sized pot of water to a boil. Add quinoa, lower heat to simmer and cook for 10 to 12 minutes. Taste after 10 minutes to check for doneness. Drain and rinse with cold water. Set aside.
Meanwhile place the finely diced tomatoes in a mesh sieve over a bowl and sprinkle with ½ a teaspoon of salt. Stir and let stand while you prepare the rest of the ingredients.
For the parsley, cut off the thicker stems. Place parsley leaves and finer stems in a food processor and pulse until finely chopped. Or finely chop by hand.
Mix together the lemon juice, olive oil, garlic and 1 teaspoon of salt.
In a large bowl mix together the cooled quinoa, finely diced and drained tomatoes, finely diced cucumbers, green onions, parsley, and mint. Drizzle the lemon juice mixture over top and mix well to coat everything. Taste and adjust seasonings if necessary.
For best flavour, cover and let sit in the refrigerator, or at room temperature, for 20-30 minutes to let the ingredients marinate in the dressing.