Add tomatoes and pasta sauce to a 3-6 quart slow cooker.
Whisk together cream and corn starch and add to the slow cooker. Stir in garlic, salt, basil and pepper.
Add chicken breasts and press down into the sauce.
Cook on low for 3-5 hours, until a meat thermometer reads 165 degrees F. The exact cook time will depend on your slow cooker -- a fuller slow cooker will take longer to cook, so a larger one will cook faster.
Stir in fresh basil and serve over pasta, rice, or with a salad and veggies!