Heat oven to 350⁰ F. On a rimmed baking sheet, spread pistachios (shelled, of course) in an even layer and toast for 5 minutes. Remove from oven and let cool enough to handle, then roughly chop.
Meanwhile, put asparagus in a steam basket. Put 1” water in the bottom and bring to boil. Place steam basket on top, cover and cook briefly until tender but with some crunch, 5 minutes or less. Remove from heat and either run under cold water or put in ice water to stop cooking process.
Combine onion, lemon juice, a pinch of salt and the pepper in a bowl and let it sit for a few minutes. Finely chop herbs while you wait. Whisk oil into lemon juice, then stir in pistachios, cheese and 3 tablespoons of chopped herbs.
To serve, put asparagus on a platter, spray or drizzle a little olive oil directly onto the asparagus. Spoon dressing onto the asparagus. Add rest of herbs and more cheese, if you want (I didn’t think it needed more than the dressing).