Bring a large pot of salted water to a rolling boil, then add the pasta. Cook until just al dente, about 8-10 minutes, stirring occasionally. Drain, reserving about a cup of pasta water.
While pasta cooks, finely grate the lemon zest and juice half of the lemon into a small bowl. Set aside.
Heat the olive oil in a large skillet over medium heat until shimmering and fragrant. Add the minced garlic and sauté for about 30 seconds until it becomes aromatic and just begins to turn golden.
Add the frozen peas directly to the skillet. Cook for about 2 minutes, stirring gently, until the peas are bright green and tender, with a slight crackle.
Transfer the drained pasta to the skillet with the peas. Toss gently to combine, letting the pasta absorb some of the garlic and olive oil.
Pour in the lemon juice and zest, then add a splash of the reserved pasta water to loosen the sauce. Toss everything together until evenly coated and glossy.
Sprinkle the grated Parmesan over the pasta and toss again to melt the cheese into the sauce, creating a rich, flavorful coating.
Finish by stirring in the chopped fresh herbs and seasoning with salt and freshly ground black pepper to taste. Toss everything once more to distribute evenly.
Check the seasoning and acidity, adding more lemon juice or herbs if desired. Serve immediately with extra cheese and herbs on top for a bright, inviting presentation.
