In a large bowl, add the stew meat cubes and balsamic vinegar. Place in the refrigerator and let marinate overnight. When ready to use, drain off the balsamic vinegar and discard.
In a large heavy pot over medium-high heat, add olive oil. Add stew meat and brown on all sides. If a lot of liquid accumulates while browning, drain into a bowl and save for later to add back to the stew.
Reduce heat to medium-low. Add the bay leaves, thyme, garlic, and tomato paste and cook until garlic is fragrant.
Add the rosemary leaves, beef stock, wine, and water. Cover with a lid and bring just to a boil over medium-high heat; reduce heat to medium and simmer approximately 1 1/2 hours or until meat is fork tender but not falling apart. Check on the meat now and then to make sure liquid does not evaporate, adding a little water if necessary. You want the resulting juice to be concentrated with flavor.
Always cook stews at low temperatures; the surface of the liquid should barely move. When you simmer very gently, the fat melts out of rich meats and mingles with the liquid. The dish can then be chilled, and the fat easily skimmed off.
After the stew beef is cooked, add potatoes, carrots, onions, and mushrooms. Bring back to a simmer and cook approximately 45 minutes, stirring occasionally, or until vegetables are cooked. Optional: At this point, you may add the cornstarch mixture if you want a thicker stew. Stir mixture into the stew until slightly thickened.
Add fresh parsley, and salt and pepper to taste.
Serve with a good sourdough bread to soak up some juice and a simple green salad.
* Such as boneless beef chuck, trimmed of excess fat and cut into bite-sized pieces.
** Check out Karen's recipe for easy-to-make homemade Beef Stock. If you don't have homemade beef stock, you may substitute a good-quality store-bought broth.
Balsamic Beef Stew Recipe: https://whatscookingamerica.net/karencalanchini/balsamicbeefstew.htm