Montpellier Butter (Green Butter)

Ingredients

Equipment Needed

• •3-quart saucepan
• •Digital scale accurate to 1 g
• •Clean lint-free kitchen towel
• •3-to-4-cup food processor
• •Fine-mesh sieve and flexible spatula
• •Wooden spoon

Instructions

1. 1

   Measure the yolks

   Hard-boil one egg for ten minutes, cool it completely in cold water, and remove the yolk. Weigh out 14 g, about three-quarters of the yolk, and save the remainder and white for another dish. Whisk one pasteurized raw yolk just enough to combine it, then weigh out 9 g. These small measurements preserve the source formula's exact balance without leaving you with a brigade-sized bowl of butter.

2. 2

   Blanch the greens

   Bring a large saucepan of water to a full boil. Add the watercress, parsley, chervil, chives, tarragon, shallot, and spinach together, submerge them with a spoon, and boil for exactly two minutes. Drain immediately and cool under very cold water to stop the cooking. The blanch softens the herbs enough to become a unified paste and steadies their green color; raw chopped herbs would leave the butter coarse and grassy.

   Keep the five principal herbs equal by weight, not by handful. Chervil is far lighter than chives, so equal-looking bunches do not preserve the formula.
3. 3

   Press completely dry

   Gather the cooled greens and shallot in a clean lint-free towel, twist the bundle tightly, and press until no more water escapes. Open the towel, loosen the greens, then twist and press once more. This is the step that decides the butter. Water left in the leaves dilutes the flavor and works against the emulsion; if the towel still feels wet beneath the bundle, keep pressing.

4. 4

   Make the green paste

   Put the pressed greens and shallot in a small food processor with the capers, gherkins, garlic, and rinsed anchovy. Process in short bursts, scraping the bowl often, until the mixture becomes a very fine, evenly green paste with no visible pieces of gherkin or leaf. A mortar gives the same result through patient pounding; the processor simply supplies the missing pair of brigade hands.

5. 5

   Work in the butter

   Add the softened butter in three portions, processing briefly after each until no pale streaks remain. Add the hard-boiled yolk and work it in completely, then add the measured raw yolk and process again until smooth. This sequence builds Montpellier Butter (No. 153) as the source directs: aromatic paste first, butter second, cooked and raw yolks only after the butter is fully incorporated.

6. 6

   Emulsify with oil

   Run the processor on low and add the oil drop by drop for the first tablespoon, then in the thinnest steady thread you can manage. Stop once or twice to scrape the bowl. The mixture should loosen slightly while staying dense, glossy, and entirely unified. If oil beads appear and the butter turns slick, stop immediately. Ça se rattrape: chill the processor bowl for ten minutes, then pulse in short bursts until it comes together. If the mixture instead looks grainy because the butter became too cold, warm the outside of the detached bowl in lukewarm water for five seconds, dry it, and pulse again.

   Butter, yolks, and oil should all be at a cool room temperature. A greasy butter is too warm; a hard butter cannot accept the oil smoothly.
7. 7

   Sieve and season

   Press the butter through a fine-mesh sieve with a flexible spatula, working in small portions and scraping the smooth green butter from the underside. The sieve replaces the old tammy cloth, but the passing itself stays: it removes herb fibers and gives the butter its proper satin finish. Beat it vigorously with a wooden spoon until smooth, then season with the measured salt and cayenne. Taste before adding more salt, since the capers, gherkin, and anchovy have already spoken.

8. 8

   Chill and serve

   Pack the Beurre Montpellier into a shallow bowl, press parchment or reusable wrap directly against the surface, and chill for at least two hours. Set it out for fifteen minutes before serving so it is cool and spreadable, not refrigerator-hard. Spoon it beside cold poached salmon or trout, or pass it with crisp toast points as an appetizer. À table!

Chef Tips

• •Fresh chervil matters here. Dried chervil tastes dusty and cannot supply the tender green body of the source formula; if the market has none, wait for the fresh herb rather than pretending the substitution is invisible.
• •Choose a mild oil. Grapeseed works cleanly, while a gentle olive oil brings a southern note; avoid an aggressively bitter or peppery oil, which will dominate the herbs and anchovy.
• •When Beurre Montpellier is prepared specifically to form a firm coat over a whole cold fish, follow the source's own branch: omit the oil and both egg yolks, then bind the same green paste with butter alone. For a dip or spread, keep the full emulsion given here because it remains supple enough for toast and sliced fish.
• •Use pasteurized raw yolk and keep the finished butter at or below 40°F (4°C). Serve it with a dry Languedoc white such as Picpoul de Pinet, whose acidity is splendid with butter, herbs, and cold trout.

Advance Preparation

• •Make the Beurre Montpellier up to two days before serving. Cover its surface directly and keep it cold so the green stays vivid and the raw-yolk emulsion remains safe.
• •The greens may be blanched, pressed dry, and refrigerated in a tightly covered container earlier the same day. Make the full emulsion before the herbs have time to dull.
• •Do not freeze the finished butter. The egg-and-oil emulsion can weep after thawing; make the small batch, serve it generously, and refrigerate any remainder for no more than three days.

Frequently Asked Questions

Nutrition Information

1 serving (about 42g)