Boil a salted pot of water for the pasta and cook it al dente according to package directions.
When the pasta is 5 minutes away from being done, scoop out ½ cup of pasta water, set aside, then add the butter to a skillet over medium-high heat.
Once the butter melts, sprinkle the flour in and cook for 1, stirring often.
Add in the garlic, followed by wine, pasta water, lemon juice. It looks watery at the beginning, but let it cook, bubbling, for about 4 minutes or until the sauce has thickened up to your liking.
Stir in the parmesan cheese (this is when you can add also your add-ins if you wish, see notes in the recipe card).
Take the skillet off the heat, taste and season with salt & pepper as needed.
Drain the pasta, add it to the skillet and toss until coated and moist.
Toss in some chopped parsley if desired. Serve immediately.
