Bring a large pot of salted water to a boil. Add orzo and cook until al dente, according to package directions. Drain well in a colander.
In same pot, melt butter over medium heat, add onion and herbes de Provence, and cook, stirring, until softened, about 4 minutes. Whisk in soup and milk. Stir in cooked orzo and parsley. Serve with Parmesan cheese and season with pepper.