Before we get into the nitty gritty of this heaven sent vegan potato au gratin recipe, let’s chat semantics. As I’ve discovered today while writing this post, potato au gratin and scalloped potatoes are two similar but different things. According to this handy article, the difference is mainly the fact that potato au gratin is cooked in a cheesy roux, while scalloped potatoes are cooked in cream.
So what are we making today? I suppose a vegan potato au gratin scalloped potato hybrid. Personally, there’s a certain nostalgia attached to the term scalloped potatoes, while potato au gratin smacks of a technical french dish I couldn’t hope to master.
VEGAN POTATO AU GRATIN/SCALLOPED POTATOES
Vegan potato au gratin/scalloped potatoes, you ask? But how? Simple: by making a vegan roux flavoured with nutritional yeast (aka vegan parmesan) and stock powder. No garlic, no cream, no worries.
As I’ve mentioned before, I’m not normally a stock powder kind of gal, but hey, it’s the holidays! The stock powder adds a delicious depth of flavour that brings the vegan roux to life. Add in a bit of cheesiness with the nutritional yeast and it’s a done deal. Add in stuffing crumble? It’s a whole other level. Speaking of, you’ll find the recipe for the stuffing itself right here.
WHICH POTATOES TO CHOOSE
A quick potato run down: potatoes are generally either starchy, waxy, or somewhere in the middle. Starchy potatoes are good for things like mash, chips, and crispy potatoes, because their interior becomes fluffy and delicious. They don’t fare well in bakes, however, because they lose their shape. Not that cheesy potato soup is a bad thing.
Waxy potatoes have a lower starch content and higher moisture/sugar content than starchy. They hold their form very well in baking.
The winner in this instance, however, is the all rounder potato. A balance between starchy and waxy, they hold their form while being baked (while not remaining excessively firm) but also add a nice starchy cohesiveness to the ‘cheesy’ sauce.
For a baked potato dish, you want to choose a variety of potato that will stand up to being baked, but also add some starchiness to the sauce in question. My go-to are Sebago, because I can easily find them at my local health food store. I don’t find the potato options at supermarkets particularly good here in Australia. Your supermarket might be better than mine, but I tend to find that the varieties on offer are vague and rather basic.
Some other varieties, according to this article, include:
THE GLUTEN FREE AND FODMAP FRIENDLY BITS
This vegan potato au gratin/newly ordained scalloped potato hybrid is FODMAP friendly. It contains no onion or garlic, and uses Massel stock powder, which is certified FODMAP friendly and gluten free by Monash.
I personally like the creaminess that soy milk lends to this recipe (Sanitarium brand is FODMAP friendly in Australia) but some other suggestions for FODMAP friendly vegan milks are macadamia, rice, hemp, almond, and coconut milk, if made up from coconut milk powder.
To ensure the dish is gluten free, make sure you use gluten free cornflour.
Gluten free, vegan and FODMAP friendly potato au gratin with stuffing crumble
FOR THE VEGAN CHEESY SAUCE
- 4 tablespoons olive oil
- 4 tablespoons gluten free cornflour
- 3-4 cups plant milk of choice
- 6-8 tablespoons nutritional yeast
- 1 1/2 teaspoons fine salt if you’re using table salt, taste as you go
- 1 teaspoon ground nutmeg optional
- Generous cracked pepper
- Balsamic vinegar or lemon juice to taste (to replicate the acidity of hard cheese)
- Seasoning to taste
FOR THE VEGAN POTATO AU GRATIN
- 1 kg all rounder potatoes skin on (I used Sebago, see note)
- 500 g sweet potato 1 large, skin on
- 150 g vegan stuffing (scroll up for recipe intro)
TO MAKE THE STUFFING CRUMBLE
- To make the stuffing crumble, preheat the oven to 180 degrees Celsius. Place 150g of stuffing (recipe link above) on a baking tray, spread out.
- Cook the stuffing for anywhere from 10-30 minutes, depending on how much you cooked it beforehand. It needs to have crunchy edges and be mostly dry.
- Allow it to cool, and then pulse it very quickly in your food processor. You could also chop it by hand. Set aside (on a plate if it’s still warm – bowls trap heat more.)
TO MAKE THE GRATIN
- To make the roux, add the olive oil to a large saucepan and heat until warmed through. Add the cornflour, whisking thoroughly to combine. The mixture should begin to bubble and congeal straight away.
- As soon as it has, add half the plant milk, and whisk well to combine. Add the other half, along with the nutritional yeast.
- Continue to stir over a low medium heat, until the mixture has thickened considerably. You’re after the consistency of cream, or a bit thicker.
- Add generous seasoning – 1/2 teaspoons good quality salt, 1 teaspoon nutmeg, loads of cracked pepper, and balsamic or lemon juice, to taste. I can’t stress enough – season to your own taste and season very generously.
- Preheat the oven to 180 degrees Celsius.
- Use a mandoline to finely slice all the potatoes. Place them into a large mixing bowl.
- 10. Pour the roux over the potatoes and (provided the roux isn’t hot) use your hands to ensure all the potatoes are covered in roux.
- 11. Decant the mixture into your cooking vessel of choice, and arrange the potatoes disks facing up. Pop in the oven.
- 12. Cook the gratin for anywhere up to an hour or so, until the potatoes are cooked and the top golden. If at any point the top is getting too dark, place a foil tent over it. This will allow it to continue cooking without excessive browning.
- Around 15-20 minutes before you pull it out, sprinkle the stuffing crumble over the top. You can also just sprinkle it as a topping at the end, if you're worried about it getting burnt.