Heat a large pot over medium high heat, pour in enough oil to fill 1/4 inch

Season beef generously with salt and pepper

Saute meat in batches until a good sear is acheived on all sides

Transfer seared beef to plate and wipe out pot

Using same pot, melt butter over medium high heat

Add onion and saute until translucent

Add garlic and cook 1 minute, stiring constantly

Add tomato paste and cook 1 minute, stirring constantly

Add beef and sprinkle flour to coat all sides

Cook 2 minutes or until slightly toasty

Add beef broth and bring to a simmer

Add parsley, thyme and bay leaves

Cover and simmer over low heat 1 1/2 hours, stirring frequently

Skim fat with a ladle or spoon

Add potatoes, carrots, celery and tomatoes

Simmer uncovered over low heat for 1 hour, stirring frequently

When stock thickens and vegetables are tender, remove from heat

Fish out the bay leaves and add vinegar

Season well with salt and pepper and serve