This homemade vegan red onion gravy is smooth, glossy and richly flavoured – perfect for serving with a nut roast or pouring over vegan sausages and mashed potatoes. It is so simple and easy to make, just requiring a little stirring from time to time, and can be made in advance and re-heated when needed (so no frantic last-minute gravy making needed here!). And since this gravy is vegan and gluten-free, everyone at the table can enjoy it, no matter what the dietary constraints. Never again will you have to endure the pain of watching everyone at the table pouring gravy liberally all over their roast while you go without!
For the whole of my life, I have been an avid gravy eater – it’s literally my favourite part of a roast. When I was a child, after a big Sunday roast, I would pour gravy all over a piece of bread and eat it with a knife and fork! (much like Ross’s “moist maker” layer in his Thanksgiving sandwich – for any other Friends fans like me!). And then I often went back and just slurped up the rest of the gravy with a spoon too!
Sadly, since traditional gravy is nearly always made from the meat drippings, it is completely off limits to vegans and vegetarians. So, naturally, when I became vegan, I was very concerned as to how to live the rest of my life without gravy and it was one of my first priorities to create a vegan gravy option!
This vegan red onion gravy is a complete game changer! It is richly flavoured with umami-rich caramelised red onions and a little wine and marmite. And I think the best thing of all, is that it can be made in advance so that there’s no scrabbling around while serving the meal, frantically trying to make the gravy like you would have to when making a traditional gravy with meat drippings.
Obviously I’m a little biased towards plant-based eating, but from everything I’ve read and seen, it does seem to be healthier than meat-eating. So, this vegan red onion gravy is already a cut above traditional gravy on the nutrition front!
Unlike traditional gravy which is heavy on the unhealthy saturated animal fat, this vegan red onion gravy contains much healthier monounsaturated fat from the small amount of olive oil that the onions are cooked in, which makes it a more heart healthy option.
- red onions and garlic - this is where the majority of the flavour comes from. You can use brown or white onions if you prefer or if that's all you have to hand!
- vegetable stock - any vegetable stock will do. Use whichever powdered stock or stock cube you normally use. Just watch the salt content and adjust the salt you add accordingly.
- marmite (or any other yeast extract) - this gives the depth of flavour and "meatiness" but also a lovely dark brown colour. (See the substitutions section below if you hate marmite!)
- wine (red, white or rosé depending on the flavour you want) - this is optional so can be omitted entirely if you prefer.
- cornstarch - used for thickening gluten-free gravy (could use arrowroot instead if you prefer).
- Caramelize the onions (fry over a low heat for ½ hour, stirring occasionally).
- Add the garlic and cook, stirring, for a few more minutes.
- Add the rest of the ingredients (except the cornstarch) and simmer for 10 minutes.
- Strain then make a cornstarch slurry (mix the cornstarch with a little cold water to make a thin liquid).
- Whisk the cornstarch slurry into the gravy mixture over a medium heat for a couple of minutes until thickened.
The key to this sauce is in the caramelizing of the onions. You need a really low heat for this. I generally set the pan over a medium heat and warm up the oil until it is hot, then stir in the onions and turn the heat right down to its lowest setting. Then I go off to do whatever else I need to do but set a timer on my phone for 10 minutes so that I come back to stir the pan every 10 minutes until the onions are nicely browned and caramelised. If they are cooking too quickly or sticking to the pan and burning, then add a little more oil or a touch of water to loosen it up.
How do you thicken gluten-free gravy?
This gluten-free vegan red onion gravy is thickened with cornstarch rather than flour, so it has a slightly different cooking method than traditional gravy. Essentially, you make the base flavoured liquid first then, at the end, you add the cornstarch mixed with a little water and whisk over a heat to thicken it.
Cornstarch can be a little tricky to work with because it cooks and thickens VERY quickly so it can make your gravy go lumpy easily. However, if you follow my instructions, you should have no problem.
- The most important thing to remember is that you need to mix the cornstarch with a tiny bit of COLD water to make, what’s known as as “cornstarch slurry”. This looks like a thin white liquid.
- Then you add that cornstarch slurry to the hot base liquid over a heat and whisk constantly over the heat until it thickens. Make sure not to cook for too long as the cornstarch will lose its thickening qualities after about 5 minutes of boiling.
- Sometimes if you don’t whisk fast enough or, if you don’t have a whisk and just use a wooden spoon or spatula to mix it instead, it might go lumpy but DON’T WORRY! Get the gravy to your desired consistency, then just strain it through a sieve to remove any cornstarch lumps. The flavour will not be affected but it is definitely worth straining out the lumps which can ruin the mouthfeel!
- Wine - use whichever colour wine you like depending on depth and richness of flavour (or whatever open bottle you have available!). For instance, if you want a rich gravy to go with sausages and mash, then I would use red wine for the gravy, but for a roast dinner with so many competing different flavours, I would use a lighter wine like white or rosé. Don’t worry, all the alcohol is boiled off so it’s fine for serving to children! But if you do not want to add wine, then it’s also fine to leave it out entirely.
- Onions - If you only have brown or white onions, it’s fine to substitute the red onions for those! I personally like red onions best but the others will do the job as well!
- Marmite can be divisive (love it or hate it!). I find it gives a deep, slightly “meaty” flavour and obviously a lovely dark brown colour. But if you hate marmite, use an alternative yeast extract (vegemite, etc.) or you could substitute with tamari or coconut molasses for a slightly lighter flavour but still the lovely rich brown colour.
- Olive oil - you could also fry the onions in vegan butter rather than olive oil if you want that buttery flavour. I tend to use olive oil wherever possible as it’s healthier but vegan butter would also work well, flavour-wise.
- Cornstarch - this can be substituted with arrowroot if you don't have cornstarch to hand. The method will be the same for either thickening agent.
I absolutely love gravy so I have it with everything but here are some more targeted ideas for you! Serve with a nut roast and all the sides for the perfect vegan roast dinner! Or pour over mashed potatoes and vegan sausages for a plant-based sausage and mash meal! It’s also perfect for serving with pies and pasties or just with some roasted vegetables and quinoa or rice for an easy midweek meal.
Although this gravy is very easy to make, it does take quite a long time so it’s worth cooking a big batch whenever you make it and then freezing it in portions for when you might want some at other times when you might not have the time. Just defrost and then re-heat by whisking over a medium heat in a saucepan. Alternatively, you could also microwave it, whisking at intervals.
You might need to add a little more water to it when you re-heat it so just add some water or vegetable stock or, better still, if you’re cooking vegetables at the same time, add a little of the vegetable cooking water so that you can capture some of the water-soluble vitamins that might have been lost in the cooking water!
This vegan red onion gravy will keep well stored in a sealed container in the fridge for up to 3 days or in the freezer for up to 6 months.
📖 Recipe 📖
Vegan Red Onion Gravy (Gluten-Free)
- 1 tablespoon olive oil
- 2 red onion diced
- 4 garlic cloves sliced
- 500 ml vegetable stock
- 60 ml wine (optional)
- 1 teaspoon marmite
- 2 teaspoon cornstarch (or arrowroot)
- 1-2 teaspoon water
- salt and pepper
- Gently caramelise the onions by slowly frying them in the oil for 30 minutes over a low heat, stirring every 10 minutes or so, to make sure they don’t stick.1 tablespoon olive oil, 2 red onion
- Add the garlic and fry for another 10 minutes, continuing over a low heat.4 garlic cloves
- Add the stock, wine and marmite and turn the heat up to bring to a boil. Simmer for 10 minutes so that the flavours blend.500 ml vegetable stock, 60 ml wine, 1 teaspoon marmite
- Strain the sauce through a sieve into a jug then pour back into the pan. Mix the cornflour with a touch of water (only enough to stir the cornflour into a liquid state – up to 2 tsp).2 teaspoon cornstarch, 1-2 teaspoon water
- Add the cornflour slurry to the gravy and whisk quickly while the sauce simmers and thickens. It should thicken in about 2 minutes but if it doesn’t thicken enough, just add a little more cornflour slurry.
- Taste and season with salt and pepper as necessary. Serve when it has thickened to your liking.salt and pepper
- When you make the cornflour slurry, you need to add cold water NOT hot water otherwise it will go all lumpy rather than turning into a thin liquid.
- Don't panic if the gravy goes lumpy (this can happen if you don't whisk fast enough or the heat is too high or if using a wooden spoon or spatula instead of a whisk - since the cornflour cooks very easily and gels together when it cooks). It's fine - just re-strain it to get the cornflour lumps out.
- If you make it in advance and want to re-heat it, you will need to whisk it well again when re-heating (or after, in the case of microwave heating). If there are any lumps, just strain them to get a lovely smooth sauce. You might also need to add a little more water or stock when re-heating. The best thing to use would be some vegetable cooking water (if you happen to be cooking vegetables at the same time) since then you would be catching some of the water soluble vitamins that may have been lost from the vegetables while cooking.
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