A made-from-scratch Vegan Green Bean Casserole with tender green beans baked up in a deliciously creamy mushroom sauce, and topped with crispy, golden, buttery breadcrumbs and tangles of caramelized onions. This really is the ultimate way to eat green beans!
6 oz (170 grams)cremini (brown) mushrooms, about 2 heaping cups
4sprigsfresh thyme
2tablespoonsall purpose flour, plain flour in the UK
¾ cup (180 ml)vegetable stock
½ cup (120mls)unsweetened plant milk
½teaspoonfine sea salt, divided - plus more to taste
¼teaspoonfreshly ground black pepper, divided - plus more to taste
INSTRUCTIONS
Fill a kettle and boil. Put the trimmed green beans into a large saucepan and pour over the boiling water. Turn the heat to high and wait for them to come to a rolling boil then turn off the heat, drain them in a colander, and immediately rinse them with cold water. Leave to drain.
In a medium skillet over a MEDIUM heat, add 1 tablespoon of the butter. Once melted and the pan hot, add the onion and cook, stirring frequently for about 15 minutes, until really golden brown. Remove from the heat and set aside while you prepare the breadcrumbs.
Break the slices of bread into smaller pieces with your hands and add to the bowl of a food processor along with 1 tablespoon of butter, 1 whole clove of garlic, and 2 tablespoons of nutritional yeast. Process until fine crumbs. Remove the blade and stir through the sautéed onions. Set aside.
Preheat the oven to 400 °F (200 °C).
Warm the same skillet you cooked the onions in over medium heat and add the last tablespoon of butter or oil. Add the sliced mushrooms, the sprigs of thyme, and a generous pinch of salt and pepper. Sauté until the mushrooms are golden.
Add the garlic, cook for a minute more, then turn the heat down to low, remove the thyme sprigs and discard, then add the flour. Stir to coat the mushrooms and continue to cook for 1 minute to remove the raw flour taste.
Pour in about half a cup of the vegetable broth, stirring well as you go to work out any lumps, then add the remaining ¼ cup, stir again then add the plant milk, the remaining 4 tablespoons of nutritional yeast, and the remaining salt and pepper. Keep stirring until it starts to thicken. Turn off the heat, taste, and add more seasoning if necessary, then add the green beans to the sauce and stir to coat them.
If you want to bake it right there in the skillet, flatten the beans down as best you can, then spoon over the oniony breadcrumb mixture. Don't compact it. Just leave it loose and rough looking. Or transfer the saucy green beans to an ovenproof dish, then add the breadcrumb topping to the top.
Bake for 25 minutes or until the bread crumbs are golden and the sauce is bubbling around the edges.
NOTES
Storage and reheating - This recipe is best eaten on the day it's baked. The topping can get a little soggy when you reheat leftovers. Having said that though, I still enjoy it warmed up the next day. Store leftovers in an airtight container in the fridge for no more than 2 days. You can pop them in a covered dish and bake in the oven at 350°F (175 °C) for 15 to 20 minutes or until piping hot, or microwave for a couple of minutes.