Green bean casserole from scratch is not difficult but it does take some time. We’re tossing out the canned cream of mushroom soup and making our own yummy mushroom sauce along with delicious fresh fried onions. Included are steps for prepping this casserole the day before if you will be short on time the day you plan to serve this yummy side dish.

Earlier in the week, I polled my Facebook fans on their favorite Thanksgiving dish.  The answers varied, but the majority and most requested dish for a real food makeover was the infamous green bean casserole.  I don’t blame them.  There’s just something so comforting about green beans swimming in that creamy mushroom sauce and topped by those flavorful crunchy onions.

Until now I’ve only ever had green bean casserole made from canned green beans, canned cream of mushroom soup, and canned french fried onions.  While delicious, it’s DEFINITELY not real food.

What I’m sharing with you today is most definitely the real deal, my friends.  No fake food in sight.  I adapted this recipe from Alton Brown which uses fresh green beans, homemade fried onions, and a super yummy homemade cream of mushroom sauce.

I’m not gonna lie, this recipe takes longer than any other recipe I’ve ever put on the blog.  I’m usually a no muss no fuss kinda gal.  I like to post quick and easy meals that beginners can even conquer, but sometimes you have to make something a little special.  This is not complicated, but it does take longer than the processed food version.  Start to finish it took me 1 hour and 15 minutes.  If you choose to make this on Thanksgiving, you might want to prep the day before. Instructions below for that step.By prepping ahead, you could make this just as fast as the standard canned version.  Pretty sweet if you ask me!

Now just to show you, you can conquer this, here’s the visual process.


Put a 1/2 cup all purpose gluten free flour into a large bowl and season with salt.  This flour is made from garbanzo bean flour, potato starch, tapioca flour, white sorghum flour, and fava bean flour.  You could also use unbleached white flour or whole wheat flour as well.


Thinly slice onions and toss them in the flour.  Let them get really comfortable with their new gluten free friend.


In small batches fry the coated onions in your fat of choice (coconut oil, ghee, lard, tallow, etc.)  I kinda have a thing for coconut oil, so that’s what I used, but any fat that you have hangin’ around will work.  Just stay away from the industrial and hydrogenated oils.



Transfer to a plate, season with a little sea salt, and set aside.  Resist the urge to eat all of the delicious onion straws or you won’t have any for the casserole.  Now sing praises for the invention of onion rings.  Halleluiah!



Wash and trim off the stems on the green beans and cut in half in desired.  You can keep them long as well.  Whatever tickles your fancy.  My husband prefers them short, while I prefer them long.  Huh.  Isn’t that funny.  I’m 5ft and he’s 6’2″.  Go figure.



Let the green beans swirl around in the hot tub for about five minutes, aka blanch them in salted water. This tenderizes the green beans so they will be cooked through during the short 15-20 minute cooking time.



Then be really cruel and shock them in a ice water bath and set aside.  Don’t worry, they love it.



Now it’s time for the yummy mushroom sauce.  Coarsely chop the mushrooms.



Sauté them in a little butter with some sea salt, pepper and fresh garlic.

Add some gluten free flour and stir.



Add some chicken or vegetable broth.  Homemade is the healthiest option and most pleasing to the old tastebuds.



Add some cream, whole milk, or half and half.



Whisk and cook until bubbly and thickened.



Mix the green beans, mushroom sauce, and a quarter of the onions together in a casserole dish.  Top with the remaining fried onions and bake at 400 degrees for 15-20 minutes until hot and bubbly.



Now pat yourself on the back and dig in to that beauty.  You just made a SUPER delicious from scratch green bean casserole!  Sing praises again, because wow!  That’s GOOD!

How to prep the day before

  • Slice the onions and put in airtight container in the fridge.
  • Chop the mushrooms and store in airtight container for the fridge.
  • Wash, trim and blanch the green beans the day before.
  • If you are going to be very short on time on Thanksgiving, go ahead and make the mushroom sauce the day before and place in a bowl in the fridge for the next day.
  • The onions I would leave for the next day because they won’t stay fresh.

Assembling the day of

  • Dredge the onions in the flour and fry them.
  • Mix together the blanched green beans, mushroom sauce, 1/4 of the freshly fried onions, and spread into casserole.
  • Top with remainder of the fried onions and bake.

Now for the handy printable because you know this is going to be a family holiday favorite now.

green bean casserole from scratch
5 from 3 votes

Green bean casserole from scratch

A delicious green bean casserole made from scratch. No canned soups. No french fried onions.
Prep Time 20 minutes
Cook Time 20 minutes
Total Time 40 minutes
Servings 8
Author Tara Buss


  • 1 large onion or two small onions sliced thinly
  • 1/2 cup All purpose Gluten free flour unbleached white flour, or whole wheat
  • 1 tsp sea salt
  • Approx. 1/4 cup fat/oil of choice I used coconut oil You may need more.
  • 1 lb. fresh green beans
  • 2 T. butter
  • 10 oz. mushrooms coarsely chopped
  • 1 tsp sea salt adjust to taste
  • 1/4 tsp cracked black pepper adjust to taste
  • 2 cloves garlic pressed or minced
  • 2 T. flour of choice
  • 1 cup chicken or vegetable broth
  • 1 cup cream whole milk, or half and half


  1. Mix together 1/2 cup flour with 1 tsp salt in a large bowl.
  2. Toss sliced onions in the seasoned flour to lightly coat.
  3. Heat oil in a large skillet over medium high heat.
  4. When hot, add onions in small batches in hot oil. Cook on each side for 2-3 minutes until lightly golden and transfer to plate to rest.
  5. Next wash and trim ends of green beans and cut in half if desired.
  6. Blanch in boiling water for five minutes.
  7. Drain green beans and place in a ice water bath to stop cooking process and set aside.
  8. Melt butter in a large saucepan or skillet.
  9. Add chopped mushrooms to pan along with salt and pepper and sautee for about 5 minutes until softened and released liquid.
  10. Add 2 cloves of garlic and cook for one more minute.
  11. Stir in flour of choice, cook for one minute, and whisk in broth and milk.
  12. Cook for several minutes until thick and bubbly.
  13. In a casserole dish, stir together green beans, mushroom sauce, and 1/4 of the onions.
  14. Top with remainder of onions and bake at 400 degrees for 15-20 minutes until hot and bubbly and browned.
  15. Let stand for 5 minutes before serving.