Made from scratch, this is an easy vegan green bean casserole with savory mushroom gravy and baked crispy onions is a healthy and delicious side dish for your holiday table, or just whenever!
Preheat the oven to 450 degrees F. Line a rimmed baking sheet with parchment paper or lightly grease with oil.
Onions: Slice onions as uniform as possible and make sure all the pieces are separated. In a large mixing bowl, combine the onions, flour, panko and salt, toss to combine. Spread the onions evenly in a single layer on the baking sheet. Place the baking sheet pan in the oven on the middle rack, and bake until golden brown, approx. 30 minutes. Stir/toss the onions 2 to 3 times during cooking. After about 20 minutes, remove, and set aside, any onions that are cooking too fast. Once done, remove from the oven and set aside. Turn the oven down to 400 degrees F.
Green Beans: Fill a large pot 2/3 full with water and add a generous pinch of salt. Bring the water to a boil, add beans and blanch for 7 minutes. Drain beans into a colander and immediately plunge the beans into a large bowl of ice water to stop the cooking. Drain and set aside.
Mushroom sauce: In a large pan, heat oil over medium-high heat, add mushrooms and cook, stirring occasionally, until mushrooms begin to sweat and release their juices, approx. 4 to 5 minutes. Add the garlic and nutmeg, continue to cook for another 1 to 2 minutes. Sprinkle the flour over and cook, stirring constantly, for 1 minute. Add the broth and let simmer for 1 minute. Lower the heat to medium-low and add the non-dairy milk. Cook until mixture thickens, stirring occasionally, approx. 6 to 8 minutes. Taste for seasoning, add more salt + pepper to taste. Remove from heat.
Assemble & bake: Add the beans to the mushroom gravy and give a good stir. Place mixture in a baking dish and top with the baked onions. Place in oven, on the center rake, and bake until bubbly, approximately 15 minutes. If onions start to brown too much, cover with foil. Let cool slightly and enjoy.
Store: Leftovers can be kept for up to 4 – 5 days in the refrigerator.
If you don’t have panko bread crumbs available, fine ground cornmeal is a delicious substitute.
Don’t have vegetable broth on hand? Try saving and using 1 cup of the water the beans were cooked in. This worked well when I was in a pinch.
The baked crispy onions is from Alton Brown. Feel free to use store bought fried onions in place of making your own. I’ve used Traders Joe’s fried onions with delicious success. Plus, it’s one less step.
Make this gluten-free by using a gluten free flour blend, mesa flour, or oat flour.
Nutritional values are estimates only. See our full nutrition disclosure here.