Roast pine nuts in a pan on low to medium heat till nuts turn brown. Do not add any oil, dry roast only. Be patient, it takes a while for all the nuts to turn brown.
Put garlic, parmesan, olive oil, roasted pine nuts in a food processor, add wild garlic leaves in batches to process.
Add salt to taste.
Notes
You can find and forage wild garlic, also known as ramsons, in many public parks in Europe and America.
You can replace wild garlic leaves with basil leaves for basil pesto.
Wild garlic's brief season is a source of excitement in the Fine Food Specialist office. Wild garlic pesto is often used in Italian fine dining.
You can add this directly to salad, cooked meat, or simply on top of toasted bread.
If you cannot forage wild garlic where you are, most Chinese shops would sell Chinese garlic chives (also a seasonal vegetable) that can be used as a replacement. It tastes similar but the hint of garlic is a lot weaker.