Pour the chicken and sauce in the slow cooker. Cook for 4-5 hours on medium.
In a medium bowl, gently toss the tomatoes, chickpeas, bell peppers, lettuce, and cilantro. Squeeze about 2 tablespoons of lemon on the mixture and set aside.
To assemble: pour 1 cup of rice in a bowl, top with 1/2 cup of salad mixture and about 1/2 cup of chicken. (Optional: top with a drizzle of ranch dressing)