Slow Cooker Cheesy Chicken Pesto

The smell of basil and melting cheese filling the house on a rainy Saturday afternoon is something no one should have to live without. I threw this casserole together once when friends showed up unannounced and my oven was on the fritz. The slow cooker did all the heavy lifting while we sat around drinking wine and pretending we were somewhere on the Italian coast. It has been my go-to comfort dish ever since that evening.

My neighbor Karen stopped by one fall afternoon while this was cooking and literally stood in my kitchen with her eyes closed inhaling near the slow cooker. She stayed for dinner and brought a bottle of Sauvignon Blanc the next week hoping for a repeat performance.

Ingredients

• Boneless skinless chicken breasts (2 large, about 500 g, cubed): Cutting them into even pieces ensures every bite is tender and cooks at the same rate.
• Shredded mozzarella cheese (2 cups, about 180 g): Use whole milk mozzarella for the best melt, and shred it yourself if you have the patience.
• Grated Parmesan cheese (1/2 cup, 50 g): This adds a salty depth that ties the whole dish together, so do not skimp here.
• Refrigerated cheese tortellini (600 g, about 21 oz): Fresh refrigerated tortellini holds up beautifully in the slow cooker, while dried pasta can turn gummy.
• Baby spinach (2 cups, roughly chopped): A quick rough chop helps it blend seamlessly into every spoonful without overwhelming picky eaters.
• Cherry tomatoes (1 cup, halved): They burst during cooking and add little pockets of sweetness that balance the rich cream sauce.
• Onion (1 medium, finely chopped) and garlic (3 cloves, minced): These two are the quiet backbone of the entire flavor profile, so use fresh cloves, never the jarred stuff.
• Heavy cream (1 cup, 240 ml): This is what makes the sauce silky and luxurious, and there is truly no lighter substitute that works the same way.
• Basil pesto sauce (3/4 cup, 180 g): Store-bought is perfectly fine, but if you have homemade pesto sitting around this is the place to use it.
• Low-sodium chicken broth (1 cup, 240 ml): Low sodium lets you control the salt level, since the cheese already brings plenty to the table.
• Salt (1/2 tsp), black pepper (1/4 tsp), and crushed red pepper flakes (1/4 tsp, optional): Season to your taste at the end, because the flavors concentrate as everything cooks down.

Instructions

Prep the slow cooker:

Give the inside of your slow cooker a light coating of cooking spray or a drizzle of olive oil so nothing stubbornly sticks to the sides during the long cook.

Layer the chicken:

Spread those cubed chicken breasts evenly across the bottom and hit them with the salt and pepper so every piece is seasoned from the start.

Add the aromatics:

Scatter the chopped onion and minced garlic over the chicken in a loose, even layer, letting those flavors seep down into the meat as everything warms together.

Tuck in the vegetables:

Drop the halved cherry tomatoes and chopped spinach on top, spreading them out so the color is already looking gorgeous before you even turn the machine on.

Whisk the sauce:

In a mixing bowl, whisk the heavy cream, chicken broth, and pesto until the mixture is smooth and uniformly green, then pour it over everything in the slow cooker.

Add the first round of cheese:

Sprinkle one cup of mozzarella and a quarter cup of Parmesan over the saucy layers, then stir everything gently once just to combine without making a mess of it.

Cook low and slow:

Cover and cook on LOW for three hours, letting the chicken get fork-tender and the sauce thicken into something that smells impossibly good.

Stir in the tortellini:

After those three hours, gently fold in the refrigerated tortellini, re-cover, and cook on LOW for another 45 minutes to one hour until the pasta is tender and the chicken is fully cooked through.

Finish with melted cheese:

Scatter the remaining mozzarella and Parmesan on top, cover one last time, and let the residual heat melt everything into a golden, gooey blanket for about five minutes before serving.

Garnish and serve:

If you want a little extra color and a faint kick, finish with red pepper flakes and torn fresh basil leaves right before bringing it to the table.

Save

The evening I served this to my family during a power outage that somehow spared the slow cooker is the night I realized food really does hold people together.

Smart Swaps That Actually Work

Rotisserie chicken from the grocery store is a completely legitimate shortcut here. Just shred it and reduce the initial cooking time by about an hour since the chicken is already cooked through. You can also swap the spinach for kale or arugula if you want a slightly more peppery bite, and sun-dried tomato pesto creates a deeply savory twist that regular basil pesto cannot quite match.

What to Serve Alongside

A simple side salad with a sharp vinaigrette cuts through all that richness perfectly. Crusty bread for soaking up extra sauce is basically mandatory in my house. A chilled glass of Sauvignon Blanc or Pinot Grigio alongside turns a casual weeknight dinner into something that feels intentionally special.

Storing and Reheating

Leftovers keep well in an airtight container in the refrigerator for up to three days, though the tortellini will soften a bit by day two. Reheat gently in the microwave at half power or in a covered dish at 325 degrees Fahrenheit until warmed through.

• Freeze individual portions in sealed containers for up to two months, but expect the cream sauce to separate slightly when thawed.
• A quick stir and a splash of broth bring the texture right back to life after reheating.
• Always check that leftover chicken reaches 165 degrees Fahrenheit internally before serving again.

Save

Some recipes earn a permanent spot in your rotation not because they are fancy, but because they make your house smell like home with almost no effort at all.

Recipe Questions & Answers

→ Can I use frozen tortellini instead of refrigerated?

Yes, but add frozen tortellini directly only if it thaws inside the cooker; extend the final cooking by 10–15 minutes and check for tenderness to avoid an undercooked center.

→ How do I prevent the tortellini from getting too soft?

Stir refrigerated tortellini in near the end of cooking (about 45–60 minutes before serving). Avoid over-stirring and check pasta for al dente texture a few minutes early.

→ What chicken works best for faster prep?

Shredded rotisserie or pre-cooked chicken speeds things up and keeps meat juicy. If using raw chicken, cube evenly and ensure it reaches safe internal temperature during the initial cook.

→ Can I swap spinach for another green?

Yes. Kale, arugula or Swiss chard are great alternatives; tougher greens like kale benefit from a slightly longer initial cook or thinner chopping.

→ Is homemade pesto better than store-bought here?

Homemade pesto adds a fresher, brighter basil flavor, but a good-quality store-bought pesto works well and keeps the dish quick and simple.

→ How should leftovers be stored and reheated?

Cool to room temperature, refrigerate in an airtight container up to 3–4 days. Reheat gently on the stovetop with a splash of broth or cream, or microwave in short bursts to preserve texture.