Follow these steps carefully to achieve a perfectly creamy and flavorful spinach and feta pasta in under 30 minutes. The key is to multitask by preparing the sauce ingredients while the pasta cooks.

1. Cook the Pasta: Bring a large pot of water to a rolling boil. Season it generously with salt—it should taste like the sea. This is your only chance to season the pasta itself. Add your chosen pasta and cook according to package directions until it is al dente (firm to the bite). Overcooking the pasta will result in a mushy final dish.
2. Reserve the Magic Water: Just before you drain the pasta, carefully scoop out at least 2 cups of the starchy pasta water. This liquid gold is crucial for creating the creamy sauce. Set it aside. Drain the pasta in a colander.
3. Start the Sauce: While the pasta is cooking, place a large skillet or Dutch oven (large enough to hold all the pasta later) over medium heat. Add the extra virgin olive oil. Once the oil shimmers, add the thinly sliced garlic and red pepper flakes. Sauté for 1-2 minutes, stirring constantly, until the garlic is fragrant and just beginning to turn a light golden color. Be very careful not to burn the garlic, as it will become bitter.
4. Wilt the Spinach: Add the entire container of fresh baby spinach to the skillet. It will look like an impossible amount, but don’t worry. Use tongs to gently toss the spinach in the garlic-infused oil. It will begin to wilt down within 2-3 minutes. Continue to toss until all the spinach is wilted.
5. Combine and Create the Sauce: Turn the heat down to low. Add the drained pasta directly to the skillet with the wilted spinach. Add the crumbled feta cheese, the zest and juice of the lemon, and the freshly cracked black pepper.
6. Emulsify the Sauce: Immediately pour in about 1 cup of the reserved pasta water. Using your tongs, begin to stir and toss everything together vigorously. The heat from the pasta and the starchy water will start to melt the feta cheese, combining with the olive oil to create a luscious, creamy sauce that clings to every piece of pasta.
7. Adjust Consistency: Continue to toss for 1-2 minutes. If the sauce looks too thick or dry, add another splash of the reserved pasta water, a little at a time, until you reach your desired consistency. The sauce should be smooth and coat the pasta beautifully, not watery or clumpy.
8. Final Seasoning and Serving: Taste the pasta and adjust for seasoning. You may not need any extra salt due to the salty pasta water and feta, but add a pinch if necessary. Serve immediately, garnished with extra feta cheese, a drizzle of olive oil, or fresh herbs if desired.