Cook the quinoa: In a saucepan, add 1 cup of quinoa to 2 cups of water or vegetable broth. Bring to a boil, then reduce the heat and simmer for 15-20 minutes until the quinoa is tender and the liquid is absorbed. Fluff with a fork and set aside to cool.
Prep the vegetables: Wash and dice the cucumbers, tomatoes, bell peppers, red onions, and avocados. Finely chop the fresh herbs.
Prepare the dressing: In a small bowl, whisk together 1/4 cup of fresh lemon juice, 1/4 cup of extra virgin olive oil, 1 teaspoon of Dijon mustard, minced garlic, salt, and pepper to taste.
Combine the ingredients: In a large mixing bowl, add the cooked quinoa, diced vegetables, fresh herbs, and optional add-ons. Pour the dressing over the salad and toss gently to combine. Ensure the dressing coats all the ingredients evenly.
Let it chill: Cover the bowl and refrigerate the salad for at least 1 hour to allow the flavors to meld together.
Serve and enjoy: After chilling, give the salad a final toss and transfer it to a serving dish. Garnish with additional fresh herbs if desired. Serve chilled and savor the delightful flavors of the best quinoa salad.