These are my Potatoes Au Gratin, and I tried to type in what I did while I cooked them. What I mean by that is that if you have watched me cook you realize it is a process, so while the potatoes I make for Chirstmas will taste okay...  I hope I got it all in the recipe I am giving you. I also match the foods I am cooking to the whole meal so I will add other things. For instance, I added some of the honey baked ham fat to the milk mixture but that stuff doesn't really matter much. I will come back and modify it if I find missing bits.

This is my first attempt to document my cooking process. I work different than other cooks. I do some research and figure out how I think it will go. I read what ingredients other users use and figure out what I think will do. In this case, this is part of my ongoing quest to copy my aunt. My aunt Kathy makes the best potatoes au gratin, as I get older myself and my family doesn't always get to make it home to see her, I have worked and worked at ways to find something close to hers. Aunt Kathy also calls me Natey Potatey. These are my offerring to her legend.  

1 lb bacon(save grease)
2 cup milk
1 tablespoon flour
salt and pepper to taste (I do .25 tsp each, if not fresh pepper use more)
6 medium potatoes. Peeled and thinly sliced
2 cups shredded extra sharp cheddar
1 onion small
.25 cups bread crumps

Prep Notes:
I like to cut the potatoes .25 to .125 inch thick. This is the Christmas season so I am drinking scotch while cooking. What does this mean? Because of this I use a mandoline, so I can dial in the cuts. If your group likes potatoes cut them .25 thick. Otherwise let the bacon do its job. The key is to make sure the potatoes are evenly sliced so you can make sure they cook evenly.

Fry bacon, set aside and chop into bacon bits when you have a free second. Keep 3 tblspoon of the bacon grease, and try to not get the burnt bits. In a medium saucepan, cook onion until clear in bacon fat. Add flour, salt pepper. Stir. Allow time for it to bubble. add milk. stir. heat until boiling, stirring throughout. Allow 1 min of boiling. begin adding 1.5cups of the shredded cheddar slowly. If you have made an alfredo this is the same thing, except we are making cheddar sauce. The trick is to add little bits and let the sauce warm up before you add more cheese. Don't let it come to a boil while slowly adding to the roux.

Spread potatoes in a baking dish. when the cheese sauce is done add the bacon bits and stir them in. Lower the temp and let it simmer for a bit while stirring. after a few minutes take sauce and spread over the potatoes making sure to cover them all.

Bake uncovered at 375 for 1 hour. then add cheese and bread crumbs to top to make a crust and bake for an additional 15-20 minutes and potatoes are tender.

Protip: I half bake them the night before. So let them go for about 30 minutes, cover and put in fridge.  Next day I will cook them with the green bean casserole at 350 for 35 minutes or slightly longer. Make sure the potatoes are cooked through.