Pasta with Ricotta, Basil & Lemon

A classic Italian dish, this recipe comes together quickly and requires only one pot (to wash), so it is also great in the RV. The walnuts are not traditional, but I really feel they make the dish special. Recipe is easily doubled.
 
½ pound dried pasta, such as penne or orecchiette (little ears)
1 cup ricotta
¼ cup basil chiffonade, loosely packed
Zest of one lemon
Salt & pepper
About ¼ cup reserved water from cooking pasta
Handful of toasted walnuts
 
Put a pot of salted water on to boil. While the water heats, toast the walnuts in a 400° oven for four minutes, or until they are fragrant. Mix the ricotta, basil, and lemon zest together in a small bowl. Season to taste with salt & pepper. Cook pasta, according to package directions, or until al dente. Scoop out about ¼ cup of the hot pasta cooking water and set it aside. Drain pasta (do not rinse) and leave the pasta in the colander to drain.
 
Return the empty pasta cooking pot to the stove on a very low heat. Add a few tablespoons of the pasta cooking water and then stir-in the ricotta mixture. Add more pasta water, if needed, until the sauce is creamy and warm. Pour the cooked pasta back into the cooking pot and toss well with the ricotta sauce to completely coat. Divide the pasta between two plates and garnish with the toasted walnuts.
 
Serves 2.