Pass the ricotta through a fine mesh sieve and salt lightly. Check the taste. Bring a large pot of water to a roiling boil, salt abundantly, and add the pasta. Drain when al dente, saving 1/4 cup of the cooking water. Stir the water into the ricotta until well blended. Toss the pasta and ricotta together with a grinding of pepper and serve the almonds and pistachios on the side, allowing each diner to sprinkle his own top alternatively, toss the nuts with the pasta, then serve.