Place short ribs in the bottom of slow cooker and season with salt and pepper, to taste.
In a mixing bowl, whisk together condensed onion soup and chili sauce. Spoon over the ribs.
Sprinkle rosemary on top.
Cook on low for 8-10 hours.
Notes
To make this in an oven. The best way to do this, is by braising them. This means you will cook them in a little bit of liquid in an oven safe pot, that has a lid. If you do choose this method, consider adding about ½ cup of beef broth to the oven safe dish. Prepare your short ribs as directed in the recipe. Place them in the pan and add the beef broth. Cover the ribs with the lid and place in the pre-heated 350℉, oven. Let the ribs cook for about two and a half hours, or until the meat is tender and pulls apart easily.