In a small bowl whisk flour, oregano, paprika, cayenne pepper salt, and black pepper. Dredge the beef cubes in the flour mixture.
Place half the oil in a large skillet over medium heat. Place half of the beef cubes into the skillet and cook on all sides, for about 30 seconds per side, or until golden. Remove and set aside.
Add the rest of the oil and repeat with the remaining beef.
Add meat pieces to the slow cooker. Add in sweet potatoes, onion, celery, carrots, garlic, mushrooms and rosemary.
Pour in bone broth, balsamic vinegar and diced tomatoes with juice.
Season with sea salt and pepper.
Cover and cook on high for 4 to 6 hours or low for 8 to 10 hours.
Stir and enjoy while hot!