In the bottom of your slow cooker (mine is 7 quarts) whisk together the chicken broth, tomato paste, and Italian seasoning. Season the chicken breasts with salt and pepper and lay them in a single layer in the slow cooker. Add the chopped tomatoes, spreading them in an even layer on top of the chicken. Cover and cook on low heat until the chicken is tender and no longer pink inside. This takes about 5-6 hours. Remove the chicken from the slow cooker and place on a plate. Using a potato masher, mash up the tomatoes inside the slow cooker until they are broken down and form a sauce. Add all the remaining vegetables except the zucchini, and stir to coat in the tomato sauce. Add the chicken breast on top of the veggie mixture and cover. Cook until the veggies are tender, about another 45 minutes to 1 hour. When the chicken is almost done cooking, place the zucchini noodles into a colander set over a large bowl. Sprinkle lightly with salt and toss to coat. Let them sit for 20-30 minutes, tossing occasionally, until they have released some of their water. Spread the zucchini noodles over a large piece of paper towel and pat out as much excess moisture as you can. Then place them into a large bowl and toss to coat evenly with the pesto. Divide the zucchini noodles between 4 bowls and then place a chicken breast on top. Top each bowl with the veggie and tomato sauce. Garnish with Parmesan cheese and fresh basil.
