Season the beef with salt and pepper. In a large pot or Dutch oven, heat the vegetable oil over medium-high heat. Brown the beef on all sides. Remove the meat from the pot and set aside.
In the same pot, add the chopped onions, carrots, and celery. Cook until the vegetables are softened, about 5-7 minutes. Add the garlic and cook for another minute.
Stir in the tomato paste and cook for 1-2 minutes. Pour in the white wine and cook for 5 minutes, allowing the alcohol to evaporate.
Return the browned beef to the pot. Add the beef broth, bay leaf, thyme, sugar, and vinegar. Bring to a boil, then reduce heat to low. Cover and simmer for 2-3 hours, or until the meat is tender.
Remove the meat from the pot and set aside. Discard the bay leaf. Using an immersion blender, blend the sauce until smooth. Alternatively, transfer the sauce to a blender, blend in batches, and return to the pot.
In a small bowl, mix the flour with a few tablespoons of the sauce to form a slurry. Stir this mixture into the sauce and cook for a few minutes until thickened.
Stir in the heavy cream and adjust seasoning with salt and pepper.
Slice the beef and return it to the sauce. Garnish with chopped parsley.
Enjoy your meal!