Whisk together in a small bowl the sour cream, salsa, 1 teaspoon lime juice, and ½ teaspoon taco seasoning until smooth to create the dressing. Set aside.

Preheat a large skillet over medium-high heat then add the ground beef and red onion. Cook for 6-8 minutes or until no longer pink. Drain off as much excess fat from the skillet as possible before adding the remaining taco seasoning and water. Stir to combine and cook for an additional 3-4 minutes or until the liquids have evaporated and the sauce has thickened. Remove from the heat and cool to room temperature.

To the bottom of a large (12-cup capacity) trifle dish add the chopped lettuce in an even layer, followed by a layer of the black beans, then corn. Be sure to add each ingredient in an even layer to the trifle dish being careful not to mix the layers.

Spoon the cooled seasoned beef evenly over the corn layer.

Spread the reserved dressing evenly over the seasoned beef. Add an even layer of halved cherry tomatoes, followed by an even layer of shredded cheddar cheese.

In a small bowl gently toss together the diced avocado and 1 teaspoon lime juice. The lime juice helps to keep the avocado from turning brown too quickly once it is cut.

Pile the avocado pieces onto the center of the shredded cheese layer and sprinkle with the chopped fresh cilantro. If desired, you can add some crushed Dorito chips, diced red onion or any other additional garnishes to the top of the layered taco salad before serving.