Stir together the flour and 1/8 teaspoon black pepper in a shallow bowl.
Heat 2 to 3 tablespoons olive oil in a Dutch oven or large soup pot over medium-high heat.
Working in batches, toss the stew beef in the flour mixture until coated all around.
Add enough beef to cover the bottom of the pot in a single layer without crowding. Sear, turning, until browned on all sides. Remove, add a little more oil, and sear the remaining beef. Set aside.
Pour about 1 cup of the beef broth and the red wine vinegar into the pot. Scrape the bottom with a wooden spoon to loosen all the browned bits.
Return the beef to the pot. Add the remaining beef broth (4 cups total) and the bay leaves.
Bring to a boil, then reduce to a low simmer. Cover and cook for about 1 1/2 hours, skimming any foam or fat from the top as needed.
With about 20 minutes left in the simmer, stir in the tomato paste. Cover and continue cooking.
After 1 1/2 hours, add the onion and carrots. Increase the heat slightly to medium-low, cover, and cook for about 10 minutes.
Remove the bay leaves. Add the potatoes, salt, and pepper to taste. Stir well.
Cover and cook about 30 minutes, until the potatoes are tender.
Add more beef broth or water if you would like it soupier. Garnish with fresh parsley and serve hot.