Sautéed Calves’ Brains with “Hazelnut” Butter

This used to be a common bistro dish, but instead of being served with beurre noisette, which is butter that’s cooked only until its milk solids caramelize, the brains were served with beurre noir, which is butter that’s cooked until it’s actually slightly burnt. The French, who are surprisingly health conscious, although in ways different than we are in the United States, actually outlawed beurre noir because burnt milk solids are known to be carcinogenic and, as the French have long known