Place the quinoa in a saucepan and add 3 1/2 cups of water, bring to a boil then cover and reduce the heat to a simmer. This will take about 20 minutes until the quinoa is tender.
Fluff the cooked quinoa and spread it out on a cookie sheet to cool.
Preheat the oven to 350 degrees.
In a bowl combine tomatoes, cooked and cooled quinoa, parsley, lemon juice, garlic, mint, olive oil, pine nuts and season with salt and pepper.
Rinse the peppers. Remove the tops and clean out the webbing and seeds.
Stuff the peppers with the quinoa mixture and place on a pan standing upright.
Cover pan and bake for 45-50 minutes.