Place the ricotta in a sieve lined with a paper towel. Press another paper towel on top and let sit to drain excess liquid for 1 hour.
In a large bowl, mix the drained ricotta, eggs, Parmesan, salt, nutmeg, and pepper until well combined.
Gradually add all-purpose flour to the ricotta mixture, stirring until a soft dough forms. If the dough is sticky, add 1 more tablespoon of flour at a time until it is easier to work with. Dust a baking sheet with semolina flour.
Form the dough into a few ropes and then cut into bite-sized pieces. Form small, walnut-sized balls and place on the prepared baking sheet.
Chill the formed gnudi for 30 minutes to help them hold their shape better.
Bring a large pot of salted water to a boil. Gently add the gnudi and cook until they float to the top, about 3-5 minutes. Cook for 1 additional minute after they rise to the surface. Remove with a slotted spoon.