Step 1: Boil the Pasta
Bring a large pot of water to a rolling boil over high heat. Add 2 tablespoons of salt – the water should taste like the ocean! Add the pasta and cook according to package directions until al dente (usually 8-10 minutes). Stir occasionally to prevent sticking. Before draining, reserve 1 cup of the starchy pasta cooking water – this is crucial for creating a silky sauce!

Step 2: Make the Pesto (While Pasta Cooks)
While the pasta cooks, make your pesto. In a food processor, combine the basil leaves, garlic cloves, and pine nuts. Pulse 5-6 times until roughly chopped. Scrape down the sides. Add the Parmesan cheese, salt, pepper, and lemon juice if using. Pulse again to combine.

Step 3: Add Olive Oil
With the food processor running, slowly drizzle in the olive oil through the feed tube in a steady stream. Process until the pesto reaches your desired consistency – about 30-60 seconds total. You want it smooth but still with some texture. Taste and adjust seasoning, adding more salt, pepper, or lemon juice as needed. The pesto should be vibrant green, aromatic, and well-balanced.

Step 4: Drain Pasta (But Save That Water!)
Once the pasta is al dente, place your colander in the sink. Ladle out 1 cup of pasta water and set aside. Then drain the pasta in the colander. Don’t rinse the pasta! The starch clinging to it helps the sauce adhere.

Step 5: Combine Pasta and Pesto
Return the drained pasta to the empty pasta pot or transfer to a large serving bowl. Add about ¾ of the pesto sauce and toss to coat thoroughly. Add the reserved pasta water a little at a time (start with ¼ cup) and continue tossing until the sauce reaches a silky, creamy consistency that coats every strand of pasta without being dry. The pasta water helps emulsify the oil and cheese into a cohesive sauce.

Step 6: Adjust and Serve
Taste the pasta and adjust seasoning if needed. If the pasta seems dry, add more reserved pasta water or additional pesto. If you’re adding vegetables or protein, fold them in now. Serve immediately in bowls, topped with extra grated Parmesan, a drizzle of olive oil, freshly ground black pepper, and crushed red pepper flakes if desired. Enjoy while hot!