In a skillet on your stove add a bit of olive oil with your ground beef or turkey with diced onions if you want to add those. Cook until meat is no longer pink, then remove and drain grease.
Pour meat into your slow cooker. Add all other ingredients and use a spoon to fold it all together so meat is well coated with the sauce.
Put lid on and set to low for 2-4 hours on low so flavors can meld together even further. If serving for longer set to keep warm with the lid on and stir every hour to rotate. Serve on buns.