Over medium heat, in a large saucepan cook onion and garlic in hot oil for about 5 minutes or until onion is tender. Stir in broth. Bring to a boil; add uncooked rice, oregano, black pepper, salt, and paprika. Simmer covered for about 40 minutes or until rice is tender. Remove from heat and stir in tomatoes, corn, and cilantro.
Slice tops from sweet peppers; remove and discard seeds. In a 3-quart rectangular baking dish, arrange peppers in a single layer. Spoon rice mixture into sweet peppers; place pepper tops onto rice. Bake, covered, about 30-40 minutes (depending on desired tenderness of peppers) until rice mixture is heated through.