Vegan Cauliflower Cheese Gratin

A tray of vegan cauliflower cheese gratin with a pair of hands holding it

This creamy, vegan ‘cheese’ sauce is the perfect base for steamed cauliflower and broccoli to reinvent the British classic Cauliflower Cheese. A crispy topping of breadcrumbs makes it even better!!

The sauce is based off of one by Kenji at Serious Eats – I changed it to suit my tastes and I’ve used it multiple times now to make vegan mac and cheese. I think the addition of a few key things really helps. Firstly, the potato helps give the sauce a thickness and stretchiness that you can’t get from a flour-based roux. It’s the blending action on the potato that really makes this work. Secondly, adding a bit blob of something salty & savoury – my favourite is marmite and I have to say, I haven’t even been the biggest fan of marmite in the past. This sauce has changed my mind. Lastly, a bit of acidity & sweetness from the mustard (I use the French’s yellow mustard as it’s quite neutral but sweet) and apple cider vinegar. All of that together helps to create that faux cheesy effect and without having to resort to using pre-made vegan cheese (most of which smells kinda weird).

Anyway, I used this for a vegan Christmas dinner I did last year for my friends and it went down super well with everyone! I added the breadcrumbs for a crispy top but if you’re coeliac, just leave them off or use GF ones instead!

Other vegan Thanksgiving recipes:

Vegan Cauliflower Cheese Gratin

A super creamy & tangy vegan 'cheddar cheese' sauce coating steamed cauliflower and tenderstem broccoli, with a crispy breadcrumb topping.
4.41 from 5 votes
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Course: Salads & Sides
Cuisine: British
Keywords: dairy free, egg free, thanksgiving, vegan
Prep Time: 30 minutes
Cook Time: 5 minutes
Total Time: 35 minutes


For the vegan ‘cheese’ sauce:

  • 60 ml (1/4 cup) extra virgin olive oil
  • 1 white onion , finely sliced
  • 120 g (~3/4 cup) peeled, cubed potato
  • 130 g (1 cup) cashews
  • 375 g (1 1/2 cups) water
  • 1 tsp smoked paprika
  • 1 tsp garlic granules
  • 3 tbsp nutritional yeast
  • 1 tbsp marmite , soy sauce or miso (my fave is marmite)
  • 1 tbsp yellow mustard
  • 2 tsp apple cider vinegar or lemon juice
  • Salt
  • Black pepper

For the gratin:

  • 1 medium head cauliflower , cut into medium florets
  • 150 g (5.4 ounces) tenderstem broccoli (optional)
  • 3 tbsp breadcrumbs
  • 1/2 tbsp olive oil


For the ‘cheese’ sauce:

  • Heat 4 tbsp of the olive oil in a large pot over a medium-low heat. Add the onion to the pot and saute until it starts to brown slightly – about 10 minutes. Add the potato, cashews, water, smoked paprika, garlic granules, nutritional yeast, soy sauce/miso, and mustard to the pot.
  • Bring to the boil and turn down to simmer – leave for 15minutes so that the potatoes and cashews can soften.
  • Pour the contents of the pot into the jug of a high-speed blender along with the apple cider vinegar and blitz until completely smooth, adding more water as needed to get the right sauce texture (I added about 250ml/1 cup to get it thin enough). Taste and season with salt and black pepper.

For the gratin:

  • Preheat your oven grill to a medium heat and place an oven rack in the top third of the oven.
  • Pour a few cm (1-2 inch) depth of water into a large pot and set over a high heat on the stove. Once the water is boiling, add the cauliflower and broccoli to the pot. Cover with a lid, turn down the heat to low, and let the veg steam for 4 minutes until tender but still with firmness to it.
  • Drain the veg and add to a roasting dish. Pour over the 'cheese' sauce and stir to coat. Mix the breadcrumbs and oil in a small bowl until coated then scatter this over the vegetables.
  • Place under the grill in the oven and watch carefully. You want the breadcrumbs to toast and the sauce to brown slightly. This should take around 5 minutes but will depend on your grill.
  • Once finished, remove from the oven and allow to cool slightly before serving.


To make ahead:
  1. Prep the sauce and store in an airtight container in the fridge for up to 3 days.
  2. Prep the veg and, once steamed, store in an airtight container in the fridge for up to 3 days.
  3. When ready to assemble: Gently warm the sauce with an added splash of water, in a small pot on the stove, stirring often until hot. Toss with the cold vegetables in a roasting dish and continue with the recipe as usual.
To make gluten free:
Use gluten free breadcrumbs for the topping
Tried this recipe?Let me know how it went! Mention @izyhossack or tag #topwithcinnamon!