Whisk together apple cider, tomato paste, flour, Worcestershire sauce, salt and pepper in a slow cooker.
Add the sweet potatoes, onion, garlic, and rosemary and mix to combine.
Season the roast with salt and pepper, to taste, and place in the center of the slow cooker.
Cover and cook until the meat is tender - about 5-6 hours on high or 8-9 hours on low.
Transfer the roast to a cutting board and slice before serving.
Notes
To make this into a freezer meal:In a gallon-sized freezer meal bag, add all ingredients. Squeeze out as much air as possible and seal bag closed. Place freezer bag into freezer and it will last 60-90 days. When ready to use, spray inside of slow cooker with non-stick cooking spray and dump ingredients from bag into slow cooker. Place the lid on top and cook for 9-10 hours on low heat (you can cook it for 5-6 hours on high heat, but it will not be as tender as cooking it low and slow. We highly recommend low and slow!). Follow the rest of the instructions as written.