In a large bowl, combine beans, bell peppers, frozen corn, and red onion. In a small bowl, whisk together olive oil, red wine vinegar, lime juice, lemon juice, sugar, salt, garlic, cilantro, cumin, and black pepper
This makes enough for two largish salads - like two romaine hearts worth of salad. Reminds me of a dressing that a little mom-and-pop diner used to make when I was a little salad-munching kid
Reduce heat to medium-low and simmer until lentils are tender, about 30 minutes. Reduce heat to medium-low, cover, and simmer until quinoa is tender and water has been absorbed, 15 to 20 minutes. Heat lemon juice in a microwave-safe bowl in a microwave until warm, about 30 seconds