In a food processor, put together carrots, celery and apple then coarsely puree. Set aside.
Heat the olive oil in the large pan over medium/high heat. When the oil is hot, add onions then minced beef, stir continously to avoid lumps and cook until all meat has browned (about 5-10 minutes)
Add pureed vegetables, mix for a minute or two then add tomato paste. Continue to stir for about 2 minutes then add pureed vegetables, bay leaves, italian herbs, tomato sauce, diced tomatoes and fish sauce.
Turn heat into low then simmer for about 2.5 to 3 hours.
Season with salt and pepper to taste.