Using a blender, mix together the milk, cream cheese, flour, and salt until smooth. Set aside.
In a saucepan, melt butter and sauté garlic for about a minute. Add the shrimp and cook until pink, about 3-5 minutes.
Remove the shrimp and leave garlic and butter in the pan. Combine the milk mixture with the pan and stir for 4 minutes. Simmer and stir until it thickens, about 6 minutes.
Remove from heat, add grated cheese and Parmesan if using, and stir until melted.
Return the shrimp to the sauce, cook for another 5 minutes or until heated through.
Serve over cooked pasta and garnish with parsley.
Notes
This homemade shrimp Alfredo is perfect for a quick family dinner or special occasion.