Prep the Beef: Season the stewing beef generously with salt and pepper. Place the beef in a ziploc bag and add the flour over the beef. Close the ziploc bag and shake until each piece of beef is fully covered in flour. You can also do this in a bowl.
Sear the Beef: Heat the olive oil in a Dutch oven over medium-high heat. Add the beef to the pot and cook just until the meat starts to brown about 3 minutes per side. You will have to do this in 2 or 3 batches, since you do not want to crowd the meat. Remove the meat from the pot after you're done and set aside.
Cook the Mirepoix: In the same pot, you will have a lot of brown bits on the bottom. Add more olive oil if needed, then add the chopped onion, carrots and celery. Cook the vegetables until soft, about 5 minutes, stirring occasionally.
Season and Cook the Beef: Add the garlic, oregano and tomato paste to the pot and stir. Cook for 30 seconds until aromatic. Add a bit of the beef broth to the pot to deglaze all the brown bits at the bottom. Add the meat back to the pot, then the beef broth and water and season with salt and pepper. Bring to a boil, then turn down the heat to a medium, cover the pot and cook for about 30 to 45 minutes, stirring occasionally. You want to cook this for so long so that the beef becomes tender, it will melt in your mouth.
Add Barley and Cook: Add the barley to the pot, cover it and cook for another 30 minutes or until the barley is cooked through. Make sure you stir occasionally so the barley won't stick. If you find that the soup is too thick add more water as necessary until you get the desired consistency, though this is quite a thick soup.
Finish and Serve: Remove the soup from heat and garnish with fresh parsley before serving.
I used pearl barley. Pearl barley usually takes 25-30 minutes to cook and hulled barley usually takes 40-50 minutes. Barley is cooked when it's tender yet chewy. If using hulled barley, make sure you add it before covering the pot and cooking the beef.
If you can't find barley, use rice or couscous instead.
If you make this ahead of time, add the barley the day you serve it.
This can be made in a crockpot. Cook for either 4 hours on high, or 8 hours on low.
Store leftover beef barley soup in an airtight container for 3-4 days.
Reheat either in the microwave at 30 second intervals, stirring in between, or on the stovetop over medium heat.
You can also store your leftovers in the freezer up to 6 months. I find it’s easiest to first transfer the soup to the fridge to thaw overnight, then heat it up using your preferred method.