Put the quinoa and 2 cups of water into a medium-sized pot with a cover and bring to a boil. Once the water begins to boil, turn the heat down to low and cook for 15-20 minutes (still covered) until there is only a small amount of water left. Turn off the burner and keep the quinoa covered for another 10 or so minutes to allow the rest of the water to be absorbed then fluff quinoa with a fork.
While the quinoa cooks, dice the tomato (~1cm cubes), chop the parsley and dill, and finely dice the 1/2 small red onion, and add them to a large mixing bowl. Add the lemon juice and extra virgin olive oil and gently mix everything together.
When the quinoa has cooled down, but is still pretty warm, add a little (~1/2 cup) at a time to the mixing bowl with the tomato herb mixture and gently mix together until all is incorporated. The key is to get the tomato and herb mixture to release some of its flavors without causing the herbs to wilt. Add salt and pepper, to taste.
Allow to cool to room temperature if eating immediately, or store in an airtight container in the refrigerator.