Ground chuck adds more flavor to the chili, though you can also use ground turkey, pork, or chicken.
If you prefer spicier chili, feel free to increase the red pepper flakes and cayenne to taste.
This recipe can also be made on the stovetop using a Dutch oven or heavy pot if you don't have a slow cooker.
Store any leftovers in an airtight container in the refrigerator for up to three days.