Sauté aromatics: Melt butter or heat olive oil in a deep skillet over medium heat. Add garlic and lemon zest; cook for 1–2 minutes until fragrant.
Toast the orzo: Add orzo and stir for another 1–2 minutes, coating it in the butter and garlic mixture until slightly golden.
Simmer: Pour in the vegetable broth. Bring to a boil, then reduce heat and let simmer uncovered for about 10 minutes, stirring occasionally, until the orzo is tender and most of the liquid has been absorbed.
Marinate the beans: While the orzo cooks, rinse and drain the white beans. In a small bowl, toss with lemon juice and dried parsley for brightness.
Finish and serve: Stir pesto, Parmesan, and salt to taste into the cooked orzo. Fold in the marinated white beans. Adjust seasoning as needed and serve warm with extra lemon zest and Parmesan on top.