|Poisson de rivière au beurre blanc
Poissons de rivière au beurre blanc   aka river fish with white butter sauce is a light, delightful dinner.
- 6 shallots, approx 1/2 pound
- 3/4 cup cider or white wine vinegar
- 2 sticks salted butter, cut into pieces
- Peel and finely chop the shallots.
- Place in a pan (non reactive), with vinegar and a generous pinch of salt.
- Bring to boil.
- Turn heat down to simmer, leave uncovered for the vinegar to evaporate.
- Cook for ~20 min, shake the pan occasionally.
- Cook the fish as prefered.
- Include butter pieces to warm shallots and vinegar, stirring together. Do NOT boil.
- Achieve a think consistency for the sauce, then serve over the fish.