Prepare the chicken breasts by cutting them into halves or thirds if they are large to fit better in the crockpot.
In the crockpot, combine the chicken broth, diced tomatoes, diced onion, minced garlic, dried Italian herbs, paprika, salt, and black pepper. If using, add the frozen mixed vegetables as well.
Stir the ingredients together until well mixed.
Place the chicken breasts on top of the mixture in the crockpot and drizzle with olive oil or dot with butter for extra flavor, if desired.
Cover the crockpot with the lid and set it to cook on low for 6 hours or on high for 3 hours.
Once the cooking time is over, check that the chicken is fully cooked. Use two forks to shred the chicken in the sauce or leave it whole, as preferred.
Serve the chicken alongside rice, pasta, or with a side of fresh veggies.