Bring a large pot of heavily salted water to a boil.
Cook pasta until just al dente. Reserve 1 cup of pasta water before draining.
Melt butter in a skillet over medium heat. Cook shallot for 2 minutes. Add garlic for 1 minute.
Add 2½ cups of peas to the skillet. Cook for 3 minutes until bright green.
Blend the cooked peas, garlic, shallot, olive oil, lemon juice, zest, herbs, half the parmesan, and half a cup of pasta water until completely smooth.
Return sauce to the skillet over low heat. Add drained pasta and toss to coat.
Add the remaining half cup of whole peas. Toss again.
Add pasta water a splash at a time if needed to loosen the sauce.
Stir in remaining parmesan. Toss one final time.
Serve immediately with parmesan, fresh herbs, lemon zest, and olive oil