1. Place ground beef in a medium-sized skillet over medium-high heat. Season with taco seasoning, and cook until browned.
2. Meanwhile, prepare dressing. In a small blender or food processor, combine Greek yogurt, cilantro, lime juice, garlic, and salt. Blend until smooth.
3. Assemble mason jar salads. Divide each salad ingredient evenly amongst 32-oz mason jars, and layer in the following order: dressing, tomatoes, beef, cheese, bell pepper, onion, shredded lettuce. Secure with lids, and store in refrigerator until ready to eat.