Cut the beef into cubes, then heat a casserole or Dutch oven with 4-5 tablespoons of EVOO over medium heat.
Add carrots, onions, and celery with a splash of water. Cover and cook for 10 minutes or until tender.
Mix in some rosemary leaves and stir until the vegetables become mushy, then add the beef cubes and brown each side.
Sprinkle flour over the beef, then move them around using a wooden spoon. This will help form a creamy sauce base. When you can see the meat is softening, add the red wine and continue stirring.
Once the wine has evaporated, add a little bit of stock to keep it moist, then pour in a bottle of passata and cook for another 2 minutes while stirring.
Once the sauce starts to dry up, add half a liter of stock. Add the bay leaves, celery leaves, and the rest of the rosemary before seasoning with salt and pepper, then stir.
Cover and simmer for 4 hours, stirring every half hour and adding more stock if it dries out; in the last 30 minutes, remove the celery leaves, bay leaves, and rosemary branch. Continue to cook without the lid to help thicken the sauce.
Turn off the stove, stir in fresh basil (optional), and cover the sauce again while you prepare the pasta.