Add the sundried tomatoes and spinach, cooking until the spinach is wilted and shiny. Stir in the orzo, chicken broth, Parmesan cheese, and salt and then cover with a lid.
Reduce the heat to low and cook the pasta at a low simmer, stirring every 2–3 minutes. Cook the orzo until the cheese is melted, there is no more liquid, and the pasta has cooked to al dente - about 8-9 minutes.