Cook the Pasta.  I used rigatoni, but whatever pasta shape you choose to use, just cook it to package instructions.  Reserve 2 cups of the cooking water to use later in the sauce.  Drain the rest of the water, and set pasta aside.

Place the pot with the drained pasta back on the stove and simmer over low heat. To the drained pasta, add the ricotta, parsley, and lemon juice.  Slowly stir in 1 cup of the pasta cooking liquid to thin the sauce as desired.  Add more water if you want a thinner sauce. Add salt and pepper.

Taste, and adjust seasonings if needed. Serve with garlic knots and a side salad.