Preheat the oven to 200C.
In a large skillet over medium heat, add the vegan butter or olive oil, onion and garlic, and cook stirring for about 4 minutes. Add salt and pepper.
Add the flour and whisk to stir and coat the veggies. Cook for 1 minute.
Add the vegetable broth, whisking to incorporate.
Add the almond milk, continue whisking.
Cook for about 5 more minutes or until thick.
Add green beans and sliced mushrooms and give it a stir. Remove from heat.
Move everything into a casserole and cook in the oven for 20 minutes, until the beans are tender.
Serve with French fried onions on top - see the link in the ingredients list for the recipe.