Preheat oven to 375°F (190°C), and try not to judge how dirty it is.
Steam or blanch green beans for 3 minutes. Shock in cold water like a boss.
In a skillet, heat olive oil. Sauté onions and garlic for 3–4 minutes until fragrant enough to make neighbors jealous.
Add vegan chicken and cook until golden and confident, about 5 minutes.
In a bowl, whisk almond milk, arrowroot, mustard, paprika, salt, and pepper. Pretend you're in a cooking montage.
Pour the mix into the skillet. Stir until thick and creamy. Cue the satisfaction sigh.
Add green beans and cheese to the pan. Mix until everybody's getting along.
Transfer to a baking dish, smooth the top, and add crispy onions.
Bake for 25–30 minutes until golden, bubbling, and irresistible.
Let it rest for 5 minutes unless you like burning your mouth for flavor justice.