In a large slow cooker, combine tomato paste and diced tomatoes.
In a small bowl, combine smoked paprika and Italian seasoning with 1 teaspoon salt.
Place the chicken on a piece of parchment. Sprinkle the salt and pepper all over the chicken, separating into pieces to coat.
In the slow cooker, place the chicken. Add any additional spices to the parchment.
Layer olives, onion bell pepper, mushrooms, and other ingredients on top.
Cover the slow cooker and turn it down to low for 6 hours
Once the timer sounds, take out the chicken from the cooker. If possible, keep the thighs intact.
In the vegetable mixture, stir in the rosemary and 1 teaspoon of salt. Serve the sauce and vegetable mixture with the chicken.