FACT: Everybody loves potatoes au gratin.
FACT: The box of au gratin potato mix is super cheap and requires little to no effort.
...So why make your own? Because why not! It's delicious, totally worth it, just time consuming. Impress your friends!
First, make friends with your mandoline.
It's a little old. It looks like it could barely cut butter. Truth is, it can slice a whole potato super-thin in less than a minute. If you don't have one, nose around your local thrift store. Odds are they have one, and it probably won't cost more than $1.
...Anyway, on to the potatoes! This serves 4.
1 large bowl of water
1/2 an onion, sliced into rings
1/2 cup frozen broccoli, optional
2 Tbsp butter
2 Tbsp flour
1 cup milk
4oz of your favorite cheese (I used Velveeta, it works wonders)
Salt and pepper to taste
1/4 cup of your favorite shredded cheese
First, peel your potatoes. Then, use your mandoline to slice your potatoes into the bowl of water. If you don't have a mandoline, you can slice as thinly as possible with a good knife or roughly chop the potatoes instead. Set aside.
Preheat oven to 375.
Next, the cheese sauce: Melt butter in a hot pan until frothy. Add flour, stir and cook until the mixture is golden brown, about 2 minutes. Quickly stir in milk. You might get chunks at first. Just keep stirring and squishing down those chunks. When the mixture thickens to thin-gravy consistency, turn the heat off and add the first 4oz of cheese. Stir until cheese is melted. Season to taste. Since the potatoes will absorb and nullify some flavor, it's okay to make the sauce a little on the salty side. Again, be careful. Adding salt later is easy, removing too much salt is virtually impossible.
Once the cheese sauce is done, drain the potatoes and stir them in. If you're using broccoli, go ahead and throw that in too.
Grease an 8x8 Pyrex or other medium sized baking dish. Spread half of the potato mixture into the dish, layer onions on top, then top with other half of potatoes. Top this with shredded cheese. Bake covered for 1 hour, then uncovered for 20-25 minutes. You will need to let this cool for a while.