The Ultimate Homemade Green Bean Casserole Recipe

I made the mushroom sauce and green bean part of this, subbed fried onions from the store in the interest of time. I don't know if I didn't let the mushroom sauce reduce down enough or what, but this was very very liquidy when it first came out of the oven. I had to make a slurry and cook it for about 2x the time and it just overall added to thanksgiving cooking stress. It was good but not sure I'd do again, kind of a lot of work for not a big enough flavor difference compared to other green bean casserole recipes. I will say blanching the green beans this way was perfect and they held up well both with extra baking and for leftovers.