Bring a pot of water on a boil for the pasta.
Heat a large skillet over medium-high heat with olive oil and butter. Sauté asparagus and onions 2-3 minutes; add in peas toss to heat through, 2-3 minutes.
In the bowl of a food processor, add herbs, lemon zest and juice, garlic, chili pepper, pistachios, salt and pepper, and pulse-chop into a pesto. Stream in 1/4 cup EVOO with the machine on then scrape pesto into a large serving bowl. Stir in Pecorino.
Salt boiling water and cook pasta 6-7 minutes, undercooking it by 1 minute from package directions. Remove 1 cup starchy, salty cooking water, add it to pesto. Drain pasta and add it to the pesto along with the asparagus, scallions and peas; toss to combine. Drizzle with EVOO to finish.