Bearnaise Sauce for Meat Fondue (recipe)

Put wine, vinegar, parsley and onion into a blender; process briefly. (If your blender has a grate setting, process for two pulses on grate.) Pour the wine and vinegar mixture into a small saucepan; add tarragon, chervil and peppercorns. Bring to a boil; cook until the liquid has completely evaporated. Return to the blender container. Add egg yolks, dry mustard, lemon juice and tabasco. Cover and process; Remove the feeder cap from the blender lid and pour the melted butter in a steady stream while the blender continues to run, until the sauce is emulsified. Serve warm.