Bring a small pot of water to a boil, then place a strainer over the top. Add the green beans to the strainer, cover, and steam for 10-15 minutes, or until fork-tender. Set aside.
Heat a drizzle of olive oil in a medium pot over medium heat. Once the oil begins to shimmer, add the onion. Cook for 2 minutes, or until semi-translucent.
Add the mushrooms and cook for 5-6 minutes, until they have released the majority of their juices. Add 2 tablespoons of olive oil, the garlic, and soy sauce. Cook for 2-3 minutes, until the garlic is fragrant.
Stir in the flour to make a roux, then season with salt and pepper.
While stirring continuously, pour in the non-dairy milk and bring to a boil. Cook for 4-5 minutes, until the sauce has thickened.
Stir in the green beans and ½ cup (75 g) of the fried onions, until combined. Transfer to a medium baking dish and sprinkle on the remaining cup of fried onions.
Bake for 20 minutes, or until bubbling.
Need easy dinner ideas?
These meals will make your weeknights way simpler. (And tastier!)