In a sealable container, whisk vinegar, oil, lemon juice, garlic, celery seed and pepper.
Add lentils, tomato, onion, bell pepper and basil; cover and gently shake to coat with dressing. Refrigerate for at least 30 minutes.
Fill lettuce leaves with quinoa, top with lentil mixture and serve.
Recipe adapted from Slim Down Now, copyright 2015 by Cynthia Sass, MPH, RD. Published by HarperOne.