In a medium saucepan, combine the rinsed quinoa and vegetable broth (or water). Bring to a boil, then reduce heat to low, cover, and simmer for about 15 minutes, or until the quinoa is fluffy and all the liquid is absorbed. Remove from heat and let sit for 5 minutes. Fluff with a fork and allow to cool.
While the quinoa is cooling, prepare the vegetables: halve the cherry tomatoes, dice the cucumber and bell pepper, and finely chop the red onion, parsley, and mint.
In a large mixing bowl, combine the cooled quinoa, cherry tomatoes, cucumber, bell pepper, red onion, parsley, and mint.
In a small bowl, whisk together the lemon juice, olive oil, salt, and pepper until well combined.
Pour the dressing over the quinoa salad and gently toss until all ingredients are well coated.
Adjust seasoning with more salt, pepper, or lemon juice according to taste.
Allow the salad to chill in the refrigerator for at least 30 minutes to let the flavors meld together before serving.
Notes
Serve the salad in a large, shallow bowl garnished with additional parsley or mint leaves, and lemon slices on the side for an extra pop of color.