Melt butter in a small saucepan over medium heat. Whisk in flour and continue whisking for 1-2 minutes (do not let it brown).
Slowly add milk, and half & half, whisking constantly until smooth, thickened, and bubbly.
Whisk in salt, black pepper, and garlic (leave garlic raw. Do not cook).
Add parmesan cheese and whisk another 30 seconds. Remove from heat and pour into 6 inch 1/6 pans, label date, and refrigerate. Once cooled, cover and hold up to 7 days.