Cut the beef into bite-sized pieces.
Dice the onion, carrot, celery, potato, and tomato.
Heat olive oil in a pot and brown the beef.
When the beef is cooked, add the onion, carrot, and celery and sauté.
Add tomatoes and potatoes, and mix well.
Add water, tomato paste, and bay leaf, then bring to a boil.
Reduce to medium-low heat and simmer for 40 minutes.
Season with salt and pepper to taste.
Finish with parsley.