Heat a large soup pot over high heat. Add beef stew meat and sear until browned on all sides, about 8 minutes.
Remove from pot and wipe all but about 1 tablespoon excess grease out of soup pot.
Turn the heat to medium, and add onions. Let cook for 20-25 minutes, stirring occasionally, until caramelized and golden brown. Stir in garlic and cook for about one minute.
Add potatoes, beef stock, 3.5 cups water, Worcestershire sauce, bay leaf, salt, paprika, and pepper. Stir well. Bring to a boil, partially cover pot, and reduce heat to a simmer.
Let simmer for about 45-60 minutes, stirring occasionally, until beef is tender and potatoes are cooked.
Whisk together remaining ½ cup cold water and cornstarch until no lumps remain. Stir into soup and cook another 10 minutes. Remove bay leaf and serve. Top with cheddar cheese and/or green onions if desired. Enjoy!
Notes
*This soup keeps well, tightly covered in the fridge for about 4-5 days. Freeze leftovers for up to 6 weeks.*Makes about 9-10 cups soup