Wash and pat the green beans dry, then line them on a chopping board (work in batches) use a sharp chef knife to trim off the ends (the stalky part)
Place the green beans in a microwavable safe bowl, season with salt, and add water to the bottom of the bowl (about 2 tablespoons)
Cover the bowl with a cling film, using a sharp knife, poke the cling film about 3 to 4 times, this will allow the steam to escape from the bowl while cooking
Place the green beans in the microwave and cook for 3 minutes on high and 2 minutes if using Haricot verts.
Carefully remove the bowl from the microwave, check for doneness, and if it needs more time, return to the microwave and cook at 30-second intervals until tender-crisp. Do keep an eye as you can easily overcook it.
Drain any excess water in a colander, sprinkle some freshly ground black pepper and parmesan cheese (if using) on the green beans. Serve and enjoy.