Ingredients
Method
- Bring a large pot of well-salted water to a rolling boil. Add the spaghetti and cook according to package directions, usually 9 to 10 minutes. Before draining, scoop out and reserve 1 cup of the starchy pasta water. Drain the pasta (do not rinse) and set aside.
- In a large skillet over medium heat, melt the butter. Add the minced garlic and red pepper flakes, stirring constantly until fragrant, about 30 seconds to 1 minute. Be careful not to burn the garlic.
- Pour in the lemon juice and 1/2 cup of the reserved pasta water. Let the mixture come to a gentle bubble, then add the baby spinach and drained spaghetti. Toss everything together until the spinach wilts and the sauce coats the noodles. If the sauce seems dry, add an extra 1/4 cup of pasta water.
- Remove the skillet from the heat. Sprinkle in the lemon zest, Parmesan cheese, salt, and black pepper. Toss a few more times to combine, then serve immediately.
Nutrition
Notes
For a creamier sauce, substitute half the pasta water with whole milk or half-and-half.
Add protein like grilled chicken, shrimp, or salmon for a heartier meal.
To make it dairy-free, swap the butter for California olive oil and omit the Parmesan or use a vegan alternative.
Store leftovers in an airtight container in the fridge for up to 4 days.
This dish does not freeze well; best enjoyed fresh.
Avoid overcooking the pasta—al dente holds up better with the sauce.
Adjust red pepper flakes to taste if you prefer less heat.