Weed doesnt really taste that great, but maybe in a pesto the taste would be lost.

What I do recently is boil the weed prior, get rid of the resulting „tea” and then rinse it a couple of times with boiling water. Takes a lot of those water soluble plant compounds and doesn’t take away too much of the fat and alcohol soluble goodness. After drying I’ve made quite a potent oil out of it which ended up looking greenish like olive oil and honestly wasn’t too bad on a pizza or a croissant.