Step 1 of 13
Vegan Green Bean Casserole
Preheat the oven to 400°F.
Step 2 of 13
Vegan Green Bean Casserole
Spray an 8- or 9-inch square casserole dish with nonstick cooking spray. Set aside.
Step 3 of 13
Vegan Green Bean Casserole
Cut the green beans into 1 1/2-inch pieces. Slice the mushrooms, finely chop the onion, and mince the garlic.
Step 4 of 13
Vegan Green Bean Casserole
Bring a large pot of salted water to a boil.
Step 5 of 13
Vegan Green Bean Casserole
Once the water is boiling, add the green beans. Blanch for 3 minutes, until beans are bright green. Drain the green beans into a colander and rinse with cold water.
Step 6 of 13
Vegan Green Bean Casserole
Set a large pot over medium-high heat and add the olive oil. Once oil is hot, add the onions and mushrooms. Saute until the mushrooms are browned and shrunken and the onions are soft, 6-7 minutes. Add the garlic and thyme and cook until fragrant, about 30 seconds.
Step 7 of 13
Vegan Green Bean Casserole
Sprinkle the flour over the mushrooms and onions and stir with a spatula to coat. Slowly pour the vegetable broth into the pot, whisking to dissolve the flour. Pour in the nut milk, and season with salt and black pepper.
Step 8 of 13
Vegan Green Bean Casserole
Cook the sauce, whisking constantly, until it begins to bubble and thicken. Reduce the heat to medium-low and allow the sauce to simmer, whisking occasionally, until it is reduced by about half, 5-7 minutes.
Step 9 of 13
Vegan Green Bean Casserole
Add the green beans to the pot and stir to coat with sauce. Pour the green bean mixture into the prepared baking dish.
Step 10 of 13
Vegan Green Bean Casserole
Bake the casserole on middle rack of oven for 15 minutes.
Step 11 of 13
Vegan Green Bean Casserole
Open the oven and sprinkle the french fried onions in an even layer over the casserole. Continue baking until the casserole is bubbling at the edges, 5-10 minutes.
Step 12 of 13
Vegan Green Bean Casserole
Check to see that casserole is done. Remove from oven or add time as needed.
Step 13 of 13
Vegan Green Bean Casserole
Allow the casserole to rest for 10-15 minutes before serving.