Pistou is the French equivalent of pesto—meet my version. I’ve loved a lot of pestos in my time, and I never tire of playing around with different herb-nut-cheese combinations. This is one of my favorites because the pairing of fresh, bright parsley and nutty, savory walnuts works so well. It’s important to buy your nuts from a farmers’ market or reputable source that has a high product turnover. The difference in taste between stale walnuts (many of which are rancid) and fresh cannot be overstated. You’ll know that the second you bite into a sweet, fresh one.
This pistou is delicious on grilled chicken or a fillet of white fish like halibut, or as a garnish atop the asparagus velouté. It will hold for up to 3 days in the refrigerator and also freezes well (bring it to room temperature before using). Before you begin, read my final note about chopping herbs in Parsley Sauce Verte.
Ingredients
- ½ cup walnut halves
- ½ cup extra-virgin olive oil
- ½ cup finely chopped flat-leaf parsley
- ¼ cup ground Parmigiano-Reggiano cheese
- 1 teaspoon garlic paste
- 0.125 teaspoon salt
- Preheat the oven to 325°F. Spread the walnuts on a small baking sheet and toast for 3 to 5 minutes, until lightly fragrant but not overly toasted. Set aside until cool to the touch, about 10 minutes.
- Place the oil in a small bowl about 4 inches in diameter and add the parsley immediately upon chopping to prevent browning. Fresh herbs start to discolor as soon as they’re chopped; submerging them in oil helps keep their color and protects their flavor. Splash in more oil if needed to keep the parsley covered.
- In a food processor, pulse the walnuts 3 or 4 times to break them into small pieces. Add the cheese and garlic and pulse another 5 to 10 times to incorporate and evenly disperse the garlic.
- Combine the nut mixture and the parsley with its oil in a bowl and stir to mix. Adjust the consistency with more oil if necessary and then taste and adjust the seasoning.