90g(1cup)breadcrumbs(ensure gluten-free if necessary)
Preheat the oven to 180 degrees Celsius (350 degrees Fahrenheit).
Place the green beans in a pan and add water until just covered.
Bring to the boil and cook on a low heat for a few minutes.
Drain away the cooking water and set aside.
Heat up 1 tablespoon of the oil and add the sliced onion once hot.
Fry for 10 minutes until browned.
Set aside in a bowl.
Heat up the remaining oil in the same pan and add the onion and garlic once hot.
Fry for around 5 minutes, until slightly softened.
Add the mushrooms and fry for another few minutes.
Measure out the milk in a jug or other measuring container and add the cornflour (cornstarch) - mix well until it has completely dissolved, otherwise it will become lumpy when cooked.
Add the milk and cornflour mixture to the pan, along with the nutritional yeast, stock cube and salt + pepper.
Heat, stirring frequently, until thickened and just beginning to bubble.
Place the cooked beans in a baking dish - I used a 20.5 cm/8 inch pie dish.
Pour over the creamy mushroom mixture.
Add breadcrumbs to the bowl with the fried onions and mix well.
Sprinkle over the fried onion and breadcrumb mixture.
Bake in the oven for 20 minutes until golden brown.
Best enjoyed immediately, but leftovers keep covered in the fridge for up to a few days - reheat in the oven.
Be very careful with cornflour as it can easily turn clumpy. Make sure it has dissolved completely in the almond milk before adding to the pan. Stir the mixture regularly to ensure it doesn't clump. If the texture of the sauce looks too thick after you've added the cornflour, add some extra water.