Haricots Verts Beurre au Citron
For six as a side dish:
Trim the haricots verts and cook in boiling water until just tender. Refresh under cold running water.
Boil the lemon juice with salt and pepper in a small sauce pan until reduced to one tablespoon or so. Remove from the heat and swirl in a tablespoon of cold butter. Add the rest of the butter, a tablespoon at a time, rubbing against the bottom of the pan and occasionally placing the pan over a very low flame as necessary to melt the butter.
Reheat the beans if necessary and arrange on a platter. Pour the sauce over them, top with parsley, and serve immediately.