This vegan green bean casserole will steal the show at your holiday table! It's bursting with savory mushrooms and green beans in creamy white wine sauce, all topped off with crispy French fried onions.
Bring a large pot of salted water to a boil. Add the beans and boil them for about 5 minutes, until bright green and tender-crisp.
Drain the beans into a colander then rinse them well with cold water, until they feel cool. Set the beans aside.
Preheat the oven to 350°F. (Note 2)
Melt 2 tablespoons of vegan butter in a large skillet over medium heat.
Add the mushrooms to the skillet in a single layer (Note 3). Cook the mushrooms for about 5 minutes on each side, until tender and browned, and then transfer them to a plate.
While the mushrooms cook, melt the remaining tablespoon of butter in a medium pot (Note 4). Add the onion and cook it for about 5 minutes, stirring occasionally, until it becomes soft and translucent.
Add the garlic and cook it with the onion for about 1 minute more, until very fragrant.
Stir in the wine, raise the heat slightly and bring it to a simmer. Allow the wine to simmer for about 5 minutes, until reduced by about half.
Sprinkle in the flour, a bit at a time, stirring between each addition to form a paste that coats the onions.
Begin pouring in the non-dairy milk, a bit at a time, followed by the coconut milk, whisking the milk and flour mixture together between each addition.
Return the mushrooms to the skillet, and stir in the bouillon cubes and thyme.
Raise the heat and bring the liquid to a simmer. Allow the mixture to cook, stirring occasionally, until the sauce thickens slightly, about 7 minutes.
Remove the pot from heat and season the sauce with salt and pepper to taste.
Arrange the green beans in a 2 quart casserole dish, then pour the mushroom mixture over the beans. You can stir it up a bit if needed to distribute the ingredients.
Place the baking dish into the oven and bake the casserole until the sauce is bubbly, about 15 minutes.
Arrange the fried onions over the casserole and continue baking for about 5 minutes more, until they darken slightly.
When the casserole has finished baking, remove it from the oven and let it sit for about 5 minutes.
Serve.