Ingredients
1 1/2 cups low-sodium chicken broth
1 cup dry white wine (such as Sauvignon Blanc or Pinot Grigio)
1 1/2 cups finely grated Gruyere cheese (about 5–6 ounces)
2 tablespoons Dijon mustard
2 teaspoons fresh thyme leaves, plus extra for garnish
1 teaspoon kosher salt, plus more to taste
1/2 teaspoon freshly ground black pepper
1/2 teaspoon garlic powder (optional but recommended)
4 small boneless, skinless chicken breasts (about 1 3/4 to 2 pounds total)
12 ounces dry fusilli pasta
1/2 cup heavy cream or half-and-half
2 tablespoons unsalted butter (optional, for extra richness)
2 tablespoons grated Parmesan cheese (optional, for finishing)
Olive oil or nonstick spray, for greasing the slow cooker
Directions
Lightly grease the inside of your slow cooker with a little olive oil or nonstick spray. This helps keep the pasta and cheese mixture from sticking too much along the edges.
Prepare the one mixture: In a medium saucepan over low to medium-low heat, combine the chicken broth, white wine, Dijon mustard, fresh thyme, kosher salt, black pepper, and garlic powder if using. Whisk until the mustard dissolves and the liquid is steaming but not boiling.
Gradually add the grated Gruyere cheese to the warm liquid, a small handful at a time, whisking constantly. Allow each handful to melt before adding the next. You are looking for a smooth, slightly thickened sauce. If it looks a bit separated, keep whisking gently over low heat until it comes back together.
Arrange the raw chicken breasts in a single layer on the bottom of the prepared slow cooker. Scatter the dry fusilli evenly around and between the chicken breasts so the pasta is fairly level.
Pour the hot Gruyere, wine, and broth mixture evenly over the raw chicken breasts and fusilli in the slow cooker, making sure all of the pasta is moistened. Use a spoon to gently press any dry pieces of pasta down into the liquid if needed. This is the key step: one mixture, poured over everything, sets up the entire dish.
Cover the slow cooker with the lid and cook on LOW for 3 to 4 hours, or until the chicken is cooked through (165°F internal temperature) and the fusilli is tender. Avoid opening the lid during the first 2 hours so the pasta cooks evenly.
About 15 minutes before serving, pour in the heavy cream or half-and-half and add the butter if using. Gently stir, taking care not to break up the chicken too much, until the sauce loosens and becomes silky. If the sauce seems too thick, add a splash of warm chicken broth or hot water, a couple of tablespoons at a time, until you reach your preferred consistency.
Taste the sauce and adjust seasoning with a bit more salt and pepper if needed. If you like, sprinkle in the grated Parmesan and stir just until melted for a slightly sharper finish.
Serve the chicken breasts whole over a bed of the creamy Gruyere-coated fusilli, or shred the chicken in the slow cooker and stir it back into the pasta for a more rustic, all-in-one bowl. Garnish with extra fresh thyme leaves before bringing it to the table.
Variations & Tips
For a slightly lighter version, use half-and-half instead of heavy cream and reduce the butter or omit it entirely. If you prefer a stronger cheese profile, replace 1/4 to 1/3 of the Gruyere with a nutty Swiss or a bit of sharp aged Cheddar; just keep the total cheese amount the same so the sauce consistency holds. To add vegetables without complicating the method, scatter 1 to 1 1/2 cups of small broccoli florets, sliced mushrooms, or frozen peas around the chicken before pouring the one mixture over the top—choose vegetables that cook relatively quickly so they become tender in the same window as the pasta. For extra aroma, sear the chicken breasts briefly in a skillet with a little oil until lightly browned on each side before placing them in the slow cooker; this adds a fond-like depth without changing the basic process. If you need to skip the wine, substitute with additional chicken broth plus 1 tablespoon of lemon juice or white wine vinegar to keep some brightness. To make it more kid-friendly, reduce the Dijon mustard to 1 tablespoon and add a pinch of paprika instead of extra pepper. Leftovers reheat best on the stovetop over low heat with a splash of broth or milk to loosen the sauce, stirring gently so the cheese doesn’t become grainy.