Trim fat from meat and cut into ¾ -inch cubes. Season all over with salt and pepper. Heat oil over medium-high heat in Dutch oven or large heavy pot; add beef and brown all over, about 10 minutes.
Remove beef and set aside; drain off all but 2 tbsp (30 mL) fat from the pan. Reduce heat to medium and add onion. Cook, stirring until softened, about 4 minutes. Add canned tomatoes (undrained) and beef broth. Return beef to pot. Bring to boil.
Cover and transfer to 325˚F (160˚C) oven, until meat is fork-tender, about 1 ½ hours to 2 hours. Stir in diced mango, fresh tomatoes and spinach. Set aside, keeping warm.
Just before serving, prepare green beans: in large skillet, heat broth over medium-high heat. Add the beans; cover and simmer, until beans are tender, about 4 minutes. Serve beef with beans and beef cooking sauce.

Serving Suggestion

This recipe is also a great starter to a meal. Serve the warm meat mixture in small cups or bowls.