In a big pot, bring about 6 cups of water to a boil, salting the water generously with 2 tbsp of salt.
While the water is reaching a boil, mince the garlic, slice the serrano peppers, and chop parsley leaves. Make sure to leave parsley stems for the next step.
On a medium-low heat, combine olive oil, garlic, and parsley stems in a large size pan. Saute the herbs in oil for about 5-6 minutes to extract the flavors of the herbs. After 6 minutes, you can take out the parsley stems if you mind having them in the pasta.
Pour in the San Marzano tomatoes and crush the tomatoes with a potato masher creating a tomato sauce. Turn the heat up to medium and allow the sauce to simmer until the pasta is finished cooking.
At this point the pasta water should be boiling. Cook the pasta according to the package instruction. Mine was 10-12 minutes. I opted for 10 minutes for al dente.
Once the pasta is close to being cooked, pour in about 1 cup of pasta water into the sauce. Season the sauce with salt. Strain the pasta and combine. Sprinkle the chopped parsley and some grated parmesan cheese. Enjoy!