Cover the beef with water and bring just to a boil. Skim, then add onion, garlic, salt, oregano, and cumin. Simmer gently for 75 minutes until nearly tender.
Remove and discard the onion. Add rice and carrots and simmer 10 minutes.
Cook the Vegetables:
Add potatoes, pumpkin, and corn. Simmer 20 to 25 minutes until the potatoes and beef are tender without breaking apart. Add green beans for the final 8 minutes.
Place one beef piece, potato, pumpkin wedge, corn piece, carrots, beans, and rice in each bowl. Ladle over clear broth and finish with cilantro.
Notes
Add the vegetables in stages so each one keeps its shape.
Store meat and vegetables in the broth for up to three days and reheat slowly to avoid breaking the pumpkin.