Preheat oven to 180ºC (355ºF). Brush beef with oil and sprinkle with salt and peper. Heat a large non-stick frying pan over high heat and cook the beef for 5 minutes on each side or until browned. Place the beef on a baking tray and cook in the oven for a further 10 minutes. Rest for at least 10 minutes, slice thinly and top with oregano, garlic and radish. Drizzle with oil and lemon juice to serve.