Season the chicken generously with salt on both sides and place in the slow cooker.
Cover and cook on low for 4 hours.
After 4 hours, use tongs to remove the breasts and put them in a bowl. Shred the chicken with a fork.
To make the nachos, toss the shredded chicken (you should have about 2 cups from the 3 breasts) with barbecue sauce. Add a layer of chips on a sheet pan and top with half of the chicken. Sprinkle with half of the cheese, red pepper, green onions, and cilantro.
Add one final layer of chips, then top with the remaining chicken, cheese, red pepper, green onions, and cilantro. Place under the broiler until the cheese is melted (around 2 to 4 minutes). Top with sour cream.
If making extra chicken, store it in freezer bags and label them with the date. Now, you'll have chicken ready for soup, tacos, pasta, or anything you like.