Briefly boiling nettles neutralizes their sting.
Heat oil in a large skillet over medium-high heat. Add shallot, fiddleheads, morels, and puffball and cook, stirring, until tender, about 5 minutes.
Add water and miso soup mix; stir until dissolved. Bring to a boil. Add ramen noodles and nettles, and continue cooking until tender, 6 to 8 minutes. Season with salt.