Keto Green Bean Casserole
Keto side dishes don't get more classic than this green bean casserole, made with fresh green beans, browned mushrooms and a parmesan cream sauce under a crisp cheesy topping.
Of all the keto side dishes on a November table, this green bean casserole is the one worth fighting for, and you’re going to nail it on the first try. Fresh green beans, mushrooms browned in butter, a thick parmesan cream sauce, and a crunchy cheese topping baked until it crackles when the spoon goes in.
It looks and tastes like the casserole most of us grew up passing down the Thanksgiving table. There’s just no can of soup and no fried onions from a canister. It still bubbles at the edges, and someone still scrapes the browned corners off the dish when they think nobody’s looking.
The one thing this casserole asks of you is dry beans. Really dry them. You’ve got this, and I’ll walk you through it below.
Where green bean casserole comes from
Green bean casserole has an actual inventor, which is rare for a holiday dish. In 1955, Dorcas Reilly was working in the Campbell Soup Company’s test kitchen in Camden, New Jersey, and she and her team put together a recipe built on things most American kitchens already had on hand: green beans, cream of mushroom soup, milk, a splash of soy sauce and French fried onions on top.
It was easy, it was cheap, and it could sit in the oven next to everything else. That’s how it ended up on Thanksgiving tables all over the country, and why it’s still there decades later. Reilly’s original handwritten recipe card was later donated to the National Inventors Hall of Fame, which tells you how seriously people take this side.
The thing that made it work in 1955 is also what made it a carb problem. The soup is thickened with flour, and the fried onions are coated in wheat flour before they hit the fryer. Take those two out and you’re left with what was always the good part: green beans in something creamy.
A low carb green bean casserole for the Thanksgiving table
Thanksgiving is a side dish holiday. The turkey gets the photo, but the plates fill up with casseroles, and that’s usually where low carb eating falls apart. So make the sides on your table ones everybody can eat without thinking about it.
Wondering if the green bean skeptics at your table will go for it? Here’s the trick: this one leans hard on the parmesan. Cheese gets kids to eat green beans. That’s not a secret.
If you want a second casserole on the table, our broccoli cauliflower gratin is the one I’d set right beside it. And for dessert, our easy pumpkin pie cups are the little pumpkin bites I’d set out after the table’s cleared.
How it went keto
The biggest change is fresh green beans instead of canned. They stay bright green and snap a little when you bite them, and they’re a good vegetable to build a side around. USDA’s SNAP-Ed guide lists green beans at about 31 calories and 3 grams of fiber a cup, and they’re in season through summer and fall. Blanch them for four minutes, cool them fast in ice water, then spread them on a towel and pat them dry. Wet beans water down the sauce, and you end up with green bean soup under a soggy lid.
The canned soup gets replaced with a real mushroom sauce. Sliced mushrooms go into hot butter and cook until their liquid is gone and they’re brown at the edges. That browning is where the deep, savory flavor comes from. Then garlic, a little onion powder and thyme, followed by broth, heavy cream and cream cheese, whisked until smooth. Half a cup of parmesan melts in at the end and thickens it, so there’s no flour anywhere.
The topping is the clever part. The fried onions are what everyone remembers, but they’re onions in a wheat flour coating. Instead, toss parmesan with a couple of tablespoons of almond flour and some melted butter. In the oven it turns into a golden, crackly cheese crust that gives you the same crunch on top.
With all that, each serving lands at 4 grams of net carbs and 6 grams of protein, most of that protein from the parmesan, which keeps it in keto side dish territory. It feeds ten as a side, so it holds up next to the turkey and everything else.
Swaps, make-ahead and leftovers
Frozen cut green beans instead of fresh, thawed and patted very dry. Skip the blanching.
Cremini mushrooms in place of white button mushrooms, for a deeper, earthier flavor.
Vegetable broth instead of chicken broth.
Gruyère in the topping in place of half the parmesan, for a nuttier crust.
This is a good casserole to get out of the way early. Assemble it the day before, without the topping, cover it and keep it in the fridge. On Thanksgiving, sprinkle on the topping and bake it straight from the fridge, adding about ten minutes. Once dinner’s over, don’t let it sit on the counter all afternoon. The USDA’s advice on Thanksgiving leftovers is to get them into the fridge within two hours, eat them within three to four days, and reheat them to 165°F. The topping softens in the fridge, so reheat leftovers in the oven or a toaster oven rather than the microwave to crisp it back up.
Keto side dishes for Thanksgiving, answered
How many carbs are in keto green bean casserole?
4 grams of net carbs per serving, for ten servings of about half a cup. The green beans account for about half of that, so keep the portion close to what the recipe makes.
Can I use the crispy fried onions from the can?
Not if you’re keeping it keto. They’re coated in wheat flour, so the parmesan and almond flour topping takes their place here.
What other easy keto side dishes go with it?
Mashed cauliflower, a broccoli gratin or a simple green salad all sit well next to it, and they keep the whole plate low carb.
Set it next to the turkey with a big serving spoon, and save the corner piece for whoever does the dishes.
Casseroles
Casseroles
Casseroles
