Preheat the oven to its maximum.
Peel, trim and wash the asparagus, then arrange in a roasting tray. Season, drizzle with oil and roast for 20 minutes. It will shrivel. Try one stalk for doneness; it should be very tender, the colour faded, but the flavour wonderfully concentrated. Remove to a serving dish and sprinkle with balsamic vinegar or lemon juice.