Pesto season is upon us once again. Hallelujah! Last year, I hit the test kitchen for several days and developed a balanced, sure-fire formula and five wonderful pestos: Rosemary Hazelnut Pesto, Cilantro Ginger Pesto, Herb Garden Pesto, Basil Arugula Pesto, and Basil Olive Pesto. I thought those recipes would suffice for years. Silly me.
Because the first greens I spied at the opening of the Portland Farmers Market this spring were fresh sorrel and chives. I bought them both and planned to make soup. But then in the nick of time I remembered that sorrel doesn’t hold it’s gorgeous green color when heated. So why not make a creamy potato soup instead and swirl a Spicy Sorrel & Chive Pesto through it just before serving? Why not indeed.
But luckily there are so many other ways to use this pesto, because I made way more than was needed for the soup. You can spread it on sandwiches, quesadillas, hamburgers, pizza dough, or flatbread. Toss it with cooked pasta, spaetzle, or gnocchi. Drizzle it over grilled fish, an omelet, or steamed new potatoes. Mix it with mayonnaise, sour cream, or cream cheese for a tasty dip. Stir it into a quiche or savory cheesecake filling. The possibilities are nearly endless. Pesto is a cook’s best friend.
But before you run to the kitchen to whip up this pesto, let’s talk a moment about what oil to use. Cold-pressed, extra virgin olive oil is the traditional choice. That’s what I always used until a recent round of testing produced a particularly bitter pesto. I tasted the oil, thinking perhaps it had gone rancid. Nope, fresh and fragrant, with no bitter after taste. So I tasted the sorrel. Again, fresh and very lemony, with no bitterness. Then I noshed on a few toasted hazelnuts. Delish. There was simply nothing in the pesto to account for the bitterness.
Perplexed, I searched the web to see if anyone had noticed this mysterious phenomenon. Bingo! The issue was explored in the March/April 2009 issue of Cook’s Illustrated Magazine. As it turns out, extra-virgin olive oil contains bitter tasting polyphenols, which don’t usually assault your taste buds because they are coated with fatty acids. The fatty acids hold the polyphenols in check. Extreme agitation, as with a processor or blender, releases the full bitterness of the polyphenols. The magazine claims that agitation is only a problem when mixing a mayonnaise or vinaigrette, because with pesto, the other ingredients buffer the reaction. In my recent tests, however, the polyphenols wreaked havoc with the pesto, lending a sharply bitter aftertaste. From now on, for pesto, I will use either a light olive oil or a flavorless vegetable oil. Lesson learned.
Spicy Sorrel Chive Pesto
This bright, lemony pesto is balanced with the earthy flavor of toasted hazelnuts. Fresh chives and garlic, plus a bit of spicy heat, takes the flavor combination over the top.
4 ounces (1 medium bunch) fresh sorrel leaves, stripped from the center ribs
2 ounces (small handful) fresh chives
2 garlic cloves, peeled
½ cup freshly grated parmesan or other dry grating cheese, such as pecorino romano, grana padano, dry asiago, or dry jack cheese
4 ounces (1 cup) toasted, skinned hazelnuts (or lightly toasted walnuts)
½-1 teaspoon crushed red pepper
½-1 cup light olive oil (or rapeseed or canola oil)
½ teaspoon fine sea salt, or to taste
- In a processor fitted with the steel knife, process sorrel, chives, garlic, cheese, hazelnuts, and red pepper until desired consistency (chunky, smooth, or in-between).
- Add ½ cup of oil, season to taste with salt, and pulse briefly to distribute. Add up to ½ up additional oil to achieve the desired consistency.
- Spoon the pesto into a container and cover with a tight fitting lid. Frig until needed. Pesto keeps, covered and chilled, for about two weeks.
Makes about 2 cups.