Heat 2 tablespoons salted butter in a large skillet over medium-high heat until melted.
Add the 2 minced shallots and cook, stirring frequently, about 3 minutes until softened.
Add 1 1/2 cups orzo and cook, stirring occasionally, about 5 minutes to lightly toast the orzo.
Stir in 3 minced garlic cloves and 1 tablespoon lemon zest and cook 1 minute until fragrant.
Whisk in 2 cups chicken broth, 1 cup heavy cream, 3 tablespoons lemon juice, 1 teaspoon salt, and 1/2 teaspoon black pepper.
Bring to a boil, then reduce heat to medium-low and simmer, stirring frequently, until the orzo is tender and liquid is mostly absorbed, about 8–10 minutes.
Once the orzo is tender, remove from heat and stir in 1/2 cup freshly shredded Parmesan until melted and combined.
Stir in 2 tablespoons chopped fresh basil, adjust seasoning if needed, and serve immediately.