Grease insert of crock pot with non-stick spray. Lay the onion and bell pepper slices in the bottom of crock pot. Pour chicken broth over the veggies. Lay chicken breasts over the top of vegetables. Season chicken with salt, pepper, garlic powder and steak sauce.
Cover with lid and cook on low heat for 6 hours OR on high heat for 3 hours (or until chicken is tender and cooked through. 165 degrees F.)
Carefully remove chicken from crock pot and shred with two forks. Return to crock pot and stir to combine the shredded chicken and veggies. (There will be liquid in the crock pot but I leave it in to keep the chicken moist.)
Using a slotted spoon, scoop up chicken mixture and place inside hoagie buns. Top with two slices of cheese or Queso. (I used white Queso velveeta on ours and it was amazing. Provolone or white american would be delish, too.)