Add all the ingredients, except the vinegar and the peppercorns, to the boiling water and simmer, covered, for about 15 minutes. Add the vinegar and the peppercorns and continue cooking at a simmer for another 15 minutes or so . . .
Served directly from the court bouillon, drained a moment on a towel, sliced onto a heated serving platter with bubbling brown butter poured over is the simplest and the purest way to appreciate brains. Chopped parsley may be added; capers are often added; the butter is often black instead of brown (I don’t understand the taste for burned butter—it is, furthermore, indigestible).
Sliced thickly (or simply split, allowing a lobe per person—lambs’ brains left whole), lightly floured, and cooked in butter; dipped in batter and deep fried in olive oil, alone or in combination with vegetables; “scrambled” (stirred gently with a wooden spoon so as to damage them as little as possible) with eggs kept creamy, butter-crisp croutons scattered at the moment of serving: These and various gratins (béchamel, mornay, duxelles . . .) are all perfect methods of preparing them. See also pumpkin satchels for a gratin of brains and creamed squash or pumpkin. The flavor is attenuated and the voluptuous texture destroyed in all recipes that call for pureeing brains.