Fill a large pot with water, add a generous pinch of salt, and bring it to a rolling boil. Once bubbling, add the pasta and cook until just al dente, about 8 minutes. Drain, reserving a little pasta water, and set aside.
While the pasta cooks, zest the lemon using a microplane, revealing a fragrant, fine layer of citrus peel. Then, juice the lemon, ensuring you catch all the bright, tangy juice in a small bowl.
Heat the olive oil in a skillet over medium heat until it shimmers and smells fragrant. Add the minced garlic and sauté for about 30 seconds until it releases a fragrant aroma but hasn't browned, to avoid bitterness.
Add the thawed peas to the skillet and cook for 2-3 minutes, stirring gently, until they are heated through and slightly tender but still vibrant green.
Pour the drained pasta into the skillet with garlic and peas. Add the lemon juice and grated lemon zest, then toss everything together vigorously to coat the pasta evenly. If the mixture feels too dry, add a splash of reserved pasta water to loosen and create a silky, shiny sauce.
Season generously with salt and freshly ground black pepper, then drizzle with a little more olive oil if desired. If using, sprinkle grated Parmesan cheese over the top, tossing again to combine.
Let the pasta rest for a minute in the skillet to allow flavors to meld and the sauce to thicken slightly, then transfer to plates. Finish with a final squeeze of lemon or fresh herbs if desired for extra brightness.
