In a large pot on medium heat, add the olive oil and garlic and sauté until the garlic is fragrant and caramelized, about 3 minutes.
Add the orzo and chili flake and toss to coat in the oil. Toast the orzo in the oil for about 5 minutes, stirring frequently.
Deglaze the pan with the wine and cook until wine is fully absorbed.
Add the chicken stock, lemon juice, and milk to the pan and reduce the heat to low. Allow to cook, stirring frequently, until the liquid is absorbed.
Add the Boursin cheese, lemon zest, and green onion to the pan and stir well until the cheese is melted and the lemon zest and green onion are well incorporated.
Stir in the parmesan cheese, season with salt and pepper to taste, and serve.