This vegan roast is a one-pan, cheap, easy, and incredibly tasty dinner. Perfect for a family meal when you need something cheaper than a meat roast that still has all of the flavour! Gluten free, dairy free, paleo, vegan and low carb friendly.
Preheat the oven to 220C/425F/gas 7. Wash and dry the celeriac, then put on a large baking tray and drizzle with several tablespoons of olive oil. Top with the fresh herbs and salt & pepper. Roast in the preheated oven for about 1 to 1 and 1/2 hours, until a knife slides easily into the centre of the celeriac to show it's soft all the way through (there should be no resistance - if there is, return it to the oven for a bit longer). Quarter the onions and add to the tray halfway through. Add the green beans (frozen is fine) to the tray and return to the oven for the last 25-30 mins.
When everything is cooked through and golden, remove the onions and add to a saucepan with a small glug of oil. Put over medium heat and stir in the tamari, balsamic vinegar (if using) and the cornflour. Pour in 500ml (2 cups) of water or vegetable stock and bring to the boil, then cook until thickened (about 4-5 mins). If at this point you want it a bit thicker, then put another tablespoon of cornflour in a small bowl and stir in a little of the onion gravy to make a smooth paste. Pour back into the pan and simmer for another couple of mins.
Pour the gravy through a sieve into a bowl or jug and return the onions to the baking tray with the beans and celeriac. Serve everything covered in the gravy. It's also nice with a side salad and/or a little crunchy bread.