Heat the olive oil in a soup pot. Add onions, carrots and garlic and cook, covered, over low heat until vegetables are tender and lightly colored, about 25 minutes; stir occasionally.

Uncover, add beef stock, raise the heat, and bring to a boil. Reduce heat, cover, and simmer for about 20 minutes.

Pour the soup through a strainer, pressing hard with the back of a spoon to extract as much flavor as possible. Discard the solids and return the broth to the pot. Add rice, sherry, peppers and salt and pepper to taste. Simmer, partially covered, for about 25 minutes, or until rice is tender.

Taste, correct seasoning, and serve immediately.