Step 1: Add the Chicken to the Crock Pot - Start by placing the chicken breasts in the bottom of your crock pot in as even a layer as you can manage. No need to overthink it. I like to give the slow cooker insert a quick spray first, just to make cleanup easier later, because future me is always grateful when past me thinks ahead. The chicken is going to cook right in the sauce, so it will soak up all that tomato, garlic, and herb flavor as it gets tender.
Step 2: Pour in the Marinara and Broth - Next, pour the marinara sauce over the chicken, then add the chicken broth. The marinara gives you that rich tomato base, while the broth keeps things from getting too thick too early. This matters because the tortellini will go in later and it needs enough saucy goodness around it to cook properly. Use a spoon to gently nudge the sauce around the chicken so everything is mostly covered.
Step 3: Season the Sauce - Sprinkle in the garlic powder, onion powder, Italian seasoning, paprika, and red pepper flakes. I know it looks simple, but these little pantry seasonings do a lot of heavy lifting. The garlic and onion give the sauce a savory foundation, the Italian seasoning brings the familiar herbs, the paprika adds warmth, and the red pepper flakes give just enough tiny kick to keep the sauce from tasting flat. Stir gently around the chicken so the seasonings get into the sauce.
Step 4: Slow Cook Until Tender - Cover the crock pot and cook on high for 3 to 4 hours or on low for 6 to 8 hours. I usually choose low when I am starting it earlier in the day, because slow cooked chicken has a way of turning out extra tender. If you are running behind, high works just fine too. The main goal is chicken that is fully cooked and easy to shred. The sauce will smell incredible by this point, so do not be surprised if people start wandering into the kitchen asking what time dinner is.
Step 5: Shred the Chicken - About one hour before the cooking time is finished, remove the chicken and shred it with two forks. It should pull apart easily. I like to do this on a plate or cutting board so I can control the texture. Some folks like big rustic pieces, while I prefer smaller shreds because they tuck into the tortellini and sauce better. Once shredded, return the chicken to the crock pot and stir it back into that marinara sauce.
Step 6: Add the Tortellini and Cheeses - For the last hour of cooking, stir in the cheese tortellini, mozzarella, heavy cream, and grated parmesan. This is the moment where the recipe turns from good to really good. The cream smooths out the tomato sauce, the mozzarella melts into it, and the parmesan gives it that savory finish. Make sure the tortellini is mostly nestled down into the sauce so it can cook evenly. Add a little extra mozzarella on top if you want that gooey, cheesy layer.
Step 7: Cook Until the Tortellini Is Tender - Cover the crock pot again and let everything cook until the tortellini is tender. This usually takes about the final hour, but keep an eye on it near the end because tortellini can go from tender to too soft if left too long. Give it a gentle stir before serving. The sauce should be creamy, cheesy, and full of shredded chicken. Spoon it into bowls, add a little extra parmesan if you like, and call everyone to the table.