Brown chicken breasts: Heat oil from sun-dried tomatoes in a large skillet over medium-high. Sprinkle chicken with ½ teaspoon salt and pepper, then cook until browned, about 3 minutes per side. If chicken is difficult to turn, cook 1-2 minutes longer, until chicken releases easily from the pan. Transfer to a 6-quart slow cooker.

Cook onion, garlic, and tomato paste: Add onion to skillet, adding more sun-dried tomato oil if needed, and cook 5 minutes until browned. Add garlic and cook 2 minutes until softened. Add tomato paste and cook 2-3 minutes until fragrant.

Add broth: Stir 1 cup chicken broth into skillet, cook 1-2 minutes, stirring and scraping up any browned bits from the bottom of the pan. Transfer to slow cooker.

Cook soup: Add remaining 7 cups broth, Italian seasoning, smoked paprika, and remaining 1 ½ teaspoons salt to the slow cooker. Cover and cook on LOW 5-6 hours or HIGH 3-4 hours until chicken is cooked through.

Shred chicken: Remove chicken from slow cooker and set aside until cool enough to handle, about 10 minutes. Shred chicken, discarding skin and bones.

Add pasta, spinach, and tomatoes to soup: Meanwhile, stir in tortellini, spinach and sun-dried tomatoes to slow cooker and if heat is on low, increase to high. Cover and cook until tortellini are tender, about 10 minutes. Stir in lemon juice.

Add cream and cheeses, along with shredded chicken: Stir in heavy cream. Gradually stir in shredded cheeses until melted. Stir in shredded chicken. Taste and add more salt and pepper if needed.