Place red pepper, green pepper, garlic, chicken breast, onion, and black olives into slow cooker.
Create sauce by mixing together tomato sauce, diced tomatoes, balsamic vinegar, Italian seasoning, and salt.
Then, pour sauce on top of ingredients in the slow cooker and mix together.
Finally, create fresh herb bundle by tying thyme and rosemary together with twine. Set on top of everything in slow cooker.
Cover slow cooker and cook on high for 3-4 hours or on low for 6-8 hours.
Once the chicken has fully cooked, remove and use 2 forks to shred. Then, remove herb bundle and add the shredded chicken back in and mix.
Serve over your favorite pasta or eat by itself with a splash of balsamic vinegar and shredded parmesan on top.