Put about one-third of the dandelion greens in the food processor or blender with the olive oil and chop for a minute, scraping down the sides. Add the remaining dandelion greens in two batches, until they’re all finely chopped up.: The first pulses release bright green aromas and soften the leaves visually into ribbons and tiny flecks, and you should hear a steady chopping hum rather than a high speed whir. This initial stage ensures the oil begins to emulsify with the greens so the final texture is smoothly integrated; if you dump everything in at once the machine can struggle and leave larger fibrous bits. A common issue here is overcrowding the bowl which leads to uneven chopping, so keep this small batch approach to promote even processing and scrape down the sides when you see larger pieces clinging to the bowl.
Add the garlic cloves, pine nuts, salt, and Parmesan, and process until everything is a smooth puree.: As you add the second and third batches you will notice the mixture change from wet clumps to a uniformly chopped, nearly paste like texture with a glossy sheen. The layered addition lets the blades handle the load without overheating, preserving fresh green color and aroma. If the mixture seems dry or the motor strains, pause and scrape sides, then add another splash of olive oil to ease movement. Avoid running the processor nonstop for too long, because heat can dull the bright herbal notes.
Taste, and add more salt if necessary. If it’s too thick, you can thin it with more olive oil or water.: Once the nuts and cheese are incorporated the texture becomes richer and silkier, and you should smell warm, toasty notes from the pine nuts alongside the savory tang of the Parmesan . Processing until smooth encourages an emulsion that coats pasta and bread well. If the pesto is too coarse, add more olive oil in small amounts; if it becomes too thin, pulse briefly to retain some texture. A frequent slip up is over processing so the pesto turns runny; counter that by pulsing and checking often so you keep some character in the puree.
Taste and add more salt if necessary: After the puree reaches a pleasing consistency take a small taste, ideally on a neutral cracker or spoon, to judge seasoning. Because Parmesan can vary in saltiness, you might need a pinch more sea salt to balance the natural bitterness of the dandelion leaves . If you add too much salt, a small squeeze of lemon or a drizzle of oil can help recalibrate; the easiest way to avoid oversalting is to add gradually and taste between additions.
If it’s too thick you can thin it with more olive oil or water: The finished pesto should spread or toss easily, so adjust viscosity by adding a tablespoon at a time of olive oil or neutral water until you reach a glossy, spoonable consistency. Warm pasta cooking water is ideal for loosening the pesto when tossing through noodles because the starch helps the sauce cling. A rookie mistake is adding too much liquid at once which dilutes the flavor, so add sparingly and judge by the way the sauce clings to a spoon.