Place the chicken breasts into the bottom of a slow cooker in a single layer.
Sprinkle the chicken breasts with taco seasoning.
Add the full undrained can of diced tomatoes and green chilies (Ro*tel) to the slow cooker.
Squeeze in the juice of one-half of a fresh lime OR use 2-3 tsp. of bottled lime juice.
Spread the rotel, lime juice, and taco seasoning evenly over the chicken breasts in an even layer.
Place the lid on the slow cooker and cook on high for 2 ½ - 3 ½ hours on high, or 5-6 hours on low.
To ensure your chicken is cooked through, check the internal temperature using an instant-read digital thermometer. Chicken needs to reach a minimum internal temperature of 165F to be safe to eat.
Once the chicken is cooked through, use two forks to shred all of the chicken breasts. Stir them into the juices, letting the chicken absorb the liquid.
Add a full 15oz jar of prepared queso (or about 2 cups of homemade) to the slow cooker. Use a rubber spatula to fold the queso into the cooked and shredded chicken.
Once the queso is evenly mixed in, sprinkle the top with an optional ¼ cup of chopped fresh cilantro.
Serve immediately with your favorite taco fixings.