Cook the pasta in salted water according to the instructions on the package. It’s best al dente. Towards the end of the pasta cooking, reserve some of the pasta water, which will be used later. Save about 1/3 cup of the pasta cooking water.
Finely chop the garlic cloves. Grate the zest from the lemon and squeeze out its juice. Meanwhile, grate the Parmesan cheese. All ingredients should be prepared before you start making your dish.
In a pan, melt the butter and add olive oil. Once the butter is melted, add the chopped garlic and chili flakes to the pan. Sauté the garlic and chili flakes for just under a minute, stirring occasionally.
Next, add the lemon juice and half of the grated Parmesan. Stir – the cheese will melt quite quickly. Once the cheese has melted, immediately add the cooked pasta and mix well.
Next, add the pasta water you reserved earlier, the grated zest of a lemon, the rest of the grated Parmesan, and the finely chopped parsley to the pasta. Mix well and let it cook on the stove for another minute or two. Adding parsley is optional, but I recommend using it as it adds color, aroma, and an interesting “herbal” flavor. Serve the pasta immediately. Bon appétit!