Wahhh! My sauce broke!

My mom was trying to make her sweet potato-chipotle-maple-cream gratin thing less soupy. She thought the solution might be to make a bechamel sauce instead of just pouring the cream over the sliced sweet potatoes. I tried this out this weekend. I made the sauce (omg so tasty!), assembled the dish, and slid it into a 350 oven for an hour. When I took it out… well, it was very pretty, except for the fact that there was a centimeter of oil sitting on top of the whole thing. I spooned the oilslick off the top and cut into it. More oil beneath. ARGH! It was still quite yummy, I thought. But still, DAMN!

I must have done something wrong with the sauce. People (not me, clearly) use bechamel in lasagna all the time and it doesn’t break in the oven!

I’m so sad.