1. Cut the beef into big cubes. Place the flour in a plastic bag, season to taste with salt and black pepper, then add the beef. Shake the packet well so each cube is dusted all over with flour.
2. Heat some vegetable oil in a big pot. When the oil is very hot, add one third of the beef cubes and fry them over a high heat for a few minutes, or until well browned. Take care not to over-crowd the pan, or the beef will not brown.
3. Remove the cubes with a slotted spoon and set aside on a plate. Fry the remaining beef in another two batches, adding more oil if necessary, and set aside.
4. In the same pan, gently fry the onion until soft and golden. Add the garlic and tomato paste, stir well, and cook for a further 30 seconds.
5. Add the tinned tomatoes, beef stock and herbs. Return the browned beef cubes and their juices to the pot. Stir well and cook over a medium-low heat for 45 minutes.
6. Cut the carrots into 2-cm slices and add them to the pot. Cook for another 45 minutes, or until the beef is very soft and the carrots are tender. Stir occasionally, and add a little more stock or water if there isn’t enough gravy.
7. Trim the beans and cut them into 3-cm pieces. Add them to the pot, stir in the mayonnaise and simmer for a further 8 minutes, or until the sauce is rich and creamy and the beans are just cooked through, but still bright green.