Peel, halve lengthwise and seed the cucumber. Cut into chunks the size of large croutons or slice into thin half-moons. It depends on whether you want al dente chunks or soft, silkier petals. Both have their merits, depending on what you're serving with. Heat the olive oil in a pan. Saute the cucumber until hot and softened to your liking, about 5 minutes, depending on size. Season with salt and pepper and toss in the mint. Serve warm or at room temperature.