Preheat the broiler. Cut the bread into slices 1 to 2 inches thick. In a small bowl, mix butter, olive oil, garlic, oregano, salt and pepper. Spread the mixture evenly on the bread slices. On a medium baking sheet, arrange the slices evenly and broil 5 minutes, or until slightly brown. Check frequently so they do not burn. Remove from broiler. Top with cheese and return to broiler 2 to 3 minutes, until cheese is slightly brown and melted. Serve at once.