Roast the sunflower seeds in a pan without oil until they turn light brown. Leave to cool on a plate.
Wash the wild garlic. Spread out a tea towel, place the wild garlic on top, and pat dry with another tea towel.
Now chop the roasted sunflower seeds with the wild garlic and all the other ingredients (parsley, yeast flakes, salt, and pepper) in the food processor and mix.
Slowly add the oil through the designated opening in the food processor. My food processor from KitchenAid has something like that. Otherwise, just add it to the other ingredients.
Notes
Depending on how intense you like pesto, you could get by with it longer. I use this amount for about 500 grams of pasta - that's quite generous.