Bring a large pot of salted water to a rolling boil. Add the pasta and cook until al dente, about 8-10 minutes. Drain, reserving a cup of pasta water.
While the pasta cooks, heat a wide skillet over medium heat. Add olive oil and let it warm until shimmering and fragrant.
Add the minced garlic to the skillet. Sauté for about 30 seconds, stirring constantly, until fragrant and lightly golden.
Toss in the frozen peas, stirring to coat them with the garlic oil. Cook for 2-3 minutes until the peas are tender and start to pop.
Pour the drained pasta into the skillet with the peas. Turn the heat to low and toss to combine, ensuring the pasta is coated with the garlic and peas.
Stir in the chopped spinach and cook for another 1-2 minutes until wilted and vibrant green. If the mixture seems dry, add a splash of the reserved pasta water.
Squeeze fresh lemon juice over the pasta and toss gently. This brightens the flavors and adds a zesty note.
Sprinkle grated Parmesan cheese over the pasta and stir until melted and evenly distributed. Taste and adjust seasoning with salt and pepper.
Remove from heat and let rest for a minute. Serve immediately, garnished with extra cheese or herbs if desired.
