Beurre blanc
Beurre blanc (French pronunciation: [bœʁ blɑ̃]; lit. 'white butter') or beurre Nantais (French pronunciation: [bœʁ nɑ̃tɛ]) is a warm emulsified butter sauce made with a reduction of vinegar, lemon juice and/or white wine and shallots into which cold whole butter is slowly added and whisked. It is the classic accompaniment to pike, for which the Loire is famous, but it is also served with several other fish dishes and also with vegetables.