Preheat the oven to 400°. In a large saucepan, heat 1 tablespoon of the olive oil. Add the quinoa and toast over moderate heat, stirring, for 2 minutes. Add 3 cups of vegetable broth, season with salt and bring to a boil.
Cover and simmer the quinoa for 12 minutes. Remove from the heat and let stand for 10 minutes. Fluff the quinoa, spread it out on a baking sheet and refrigerate until it is chilled, about 20 minutes.
Add the pine nuts, diced cherry tomatoes, scallions, chopped parsley, mint and cilantro.
In a dish, combine the lemon juice, olive oil and pour over the salad.
Mix well and serve at room temperature.