Wash the green asparagus and cut off the woody ends. Wash white asparagus, peel and cut off woody ends. Clean the carrots, leaving some green, peel and cut in half lengthwise. Wash and clean the beans.
Spread the vegetables on 2 deep baking trays. Season with salt and pepper, pour 100 ml of water over each and drizzle oil over them. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 15-20 minutes.
After half the baking time, replace the trays once.
Melt the butter. Wash parsley, shake dry and chop finely, stir into the butter. Arrange vegetables, drizzle with butter.