During a very cold, rough week this winter, I was happy to find a patch of unprotected cilantro outside that had survived the weather mostly intact. In my opinion the flavor of the cilantro had in many ways improved, the plants themselves were very mature and almost ready to bolt, the weather being the only factor preventing them from doing so. When the plant gets like this, it develops an almost citrusy note similar to what you would find when tasting the seeds, which are sold as the spice coriander. I grabbed a huge bunch of it and made this sauce for the first course of our February dinner.
What you will need
One large bunch cilantro
One egg yolk (duck egg if you can get it! I recommend The Grange NC in Siler City)
One tablespoon apple cider vinegar
One bulb garlic
½ cup vegetable oil
Ice bath for shocking
Preheat the oven to 400, and at the same time put a pot of water on the stove and bring to a boil. Cut the very top off the garlic bulb making sure the cloves are exposed and that it still holds together. Coat with an incidental amount of oil, and wrap it in foil. When the oven has preheated, place it inside and set a timer for 30 minutes. When your water has come to a boil, add a good amount of salt so that it tastes like a well-seasoned soup.
Add all your cilantro to the boiling water, making sure that it is submerged well, and let it blanch for about a minute. The stems should become tender, and the color should set at a brilliant bright green. Do not over cook the cilantro, or it will turn brown. To guarantee a good result, drain the water and add the herbs to an ice bath, making sure again that everything is submerged. The cilantro itself should be cool to the touch when you remove it, and you may need to spend a few minutes stirring it around in the water.
Take a very clean dish towel, and wrap it around the herbs so that you can wring out all the excess water into the sink. You should be left with a tiny ball of very green and tender cilantro. Keep cold until you are ready to use it. When you take the garlic out of the oven, it should be very tender and pulling away from the husk it is wrapped in. After it cools, you should be able to pull apart the cloves and then squeeze out the sweet and mild roast garlic into a bowl.
Now that you have all your ingredients prepared, chop up your cilantro as fine as you can with a sharp knife, and add it to the food processor with the roast garlic, vinegar, and egg yolk. Give it a few pulses to incorporate everything, and then begin blending. While the blade is moving, start pouring the oil slowly into the top of the food processor, trying to achieve and slow and steady stream. If you go too fast, it may not emulsify properly.
What you should end up with is something with the consistency of a good mayonnaise or aioli. Remove with a rubber spatula from the processor and store in the fridge for a few hours to let all the flavors develop. We served this with roasted carrots, grilled whole hakurei turnips, and baby brassica leaves tossed in a little bit of vinegar. It should last for a while in the fridge since it is mostly just fat!