Bring a large pot of salted water to a rolling boil. Add the pasta and cook until just al dente, about 1 minute less than package instructions. Reserve 1 cup of pasta water, then drain the pasta and set aside.
While the pasta cooks, trim the tough woody ends off the asparagus, then slice diagonally into 2-inch pieces. Rinse the peas if frozen and set aside. Finely chop the garlic cloves.
Heat olive oil in a large skillet over medium heat. Add the chopped garlic and sauté for about 30 seconds, until fragrant and golden. Be careful not to burn it.
Add the sliced asparagus to the skillet and cook for 3–4 minutes, stirring occasionally, until it is tender yet still vibrant green and slightly blistered.
Stir in the peas and cook for another 2 minutes until they are heated through and slightly softened, maintaining their bright color.
Add the drained pasta to the skillet with the vegetables. Toss everything together gently over low heat, adding a splash of the reserved pasta water if needed to loosen the mixture and create a silky sauce.
Zest half of the lemon over the pasta, then squeeze in the lemon juice. Toss again to distribute the bright citrus flavor evenly.
Sprinkle the freshly grated Parmesan cheese over the pasta, then toss gently until the cheese melts slightly and coats the ingredients, adding umami and richness.
Taste and season with salt and freshly ground pepper as needed. Serve immediately, drizzled with a little extra olive oil if desired, and enjoy immediately while the flavors are vibrant and fresh.
