Pistachio Beurre Blanc Recipe
I typically serve this with cod (cheek or filet), monkfish, or lobster — but feel free to experiment. When serving with cod, I salt and portion the cod in advance then cook it sous vide with butter and lemon thyme at 128ºF until warm throughout.
EQUIPMENT
For this recipe, I use an immersion circulator to keep the sauce at temperature before serving. Unlike most beurre blanc recipes, this recipe can be kept at 140ºF almost indefinitely, making it a breeze to make ahead of time and serve a part of a multi-course meal. But this temperature control is also useful for infusing a subtle hint of kombu in the sauce.
I assume you have the other equipment — pot, whisk, blender, etc. — but you might not have a nut milk bag for straining the basil oil. Here’s the one I use.
With that said, let’s get to the recipe! I’ll split it into three parts: the basil oil, the pistachio base, and the beurre blanc. You can make the first two a couple days in advance.
BASIL OIL RECIPE
Ingredients:
A bunch of basil
Neutral oil (will use 2x of the blanched basil weight)
Steps:
De-stem basil.
Blanch for 30 seconds and add to ice bath.
Dry it really well (I squeeze it through paper towels).
Blend blanched basil with 2x weight in oil (if working with small quantity, start with all the oil and add the blanched basil a little at a time).
Keep in fridge overnight (to darken color) before straining with a nut milk bag. Lasts a couple days in fridge.
PISTACHIO BASE RECIPE
Ingredients:
Leftover fish bones (I use a full snapper carcass because I always have one around from a prior ceviche course) or 1lb of clams
2 cloves garlic (sliced)
100g unfiltered sake (unfiltered mainly for the white color)
75g water
25g white wine vinegar
Zest from one lemon
1 bay leaf
Big handful of pistachios soaked in water overnight (these are the best inexpensive pistachios I have found online)
Steps:
In small pot/saucier, soften garlic in a bit of neutral oil.
Add all the ingredients other than pistachio and simmer covered for ~10 minutes.
Strain.
Add the above strained liquid and ⅓ its weight in soaked pistachios to a blender.
Strain with fine mesh strainer. Lasts a couple days in the fridge.
PISTACHIO BEURRE BLANC
Ingredients:
Basil oil (from above)
Pistachio base (from above)
Creme fraiche (will be 25% of the beurre blanc base weight)
Unsalted butter (will be 150% of the beurre blanc base weight)
5 inch piece of kombu
Lemon juice
Salt
Peeled then semi-dehydrated cherry tomatoes (optional)
Preserved meyer lemon (optional)
Crushed roasted pistachios (optional)
Steps:
Combine and heat pistachio base and 25% its weight in creme fraiche in small pot/saucier.
Gradually add butter totally 150% weight of beurre blanc base.
This will keep at 140F almost indefinitely. I make it hours ahead and keep it at 140F with the kombu until it's time to serve.
Add back to pot (if you were keeping it sous vide). Add optional ingredients (I think of these as little flavor/texture pops that make a dish with just fish a lot more interesting) and bring to temp.
Season to taste with salt and lemon juice.
Split with basil oil and serve!