Spray the slow cooker with non-stick spray and arrange the frozen tater tots in a single, even layer across the bottom.

Heat a large skillet over medium-high. Add the ground beef and frozen peppers and onions. Brown, breaking the meat into small pieces.

Drain excess fat from the skillet. Return to the heat.

Sprinkle the taco seasoning over the meat mixture, pour in 2/3 cup water, and simmer for about 5 minutes until the mixture is saucy and slightly thickened.

Spoon the seasoned meat evenly over the tater tots in the slow cooker.

In a medium bowl, combine the sour cream and 1 cup of shredded cheddar cheese. Stir until smooth.

Spread the sour-cream-and-cheese mixture over the meat layer in the slow cooker. Smooth it gently with a spatula.

Cover and cook on LOW for 4 hours. Avoid lifting the lid during cooking so the heat stays steady.

After 4 hours, sprinkle the remaining 1 cup of cheddar cheese across the top, cover until the cheese melts (about 5–10 minutes).

Top with sliced scallions and diced tomatoes just before serving. Scoop portions so each serving gets tots, meat, and the creamy cheese layer.