Sliced red onions, marinated in red wine vinegar, olive oil and oregano make a fantastic side dish for salads and grilled meats. They’re tangy, with a bit of crunch and a lovely silky coating.

I love to serve them with salads, grilled meats, on kebabs or with a Greek mezze board.

Marinated sliced red onions in a glass jar with a metal spoon sticking out. The jar is on a vintage steel surface.

I do love to make pickled red onions, but these marinated onions are a level beyond.

The onions are pickled for just 15 minutes in salt and red wine vinegar. This gives the onions that lovely tangy kick.
Then after that initial 15 minutes, we add in plenty of olive oil and some oregano.

The result is a tangy, silky, smooth onion with a nice bit of crunch.

These are my luxury onions.

📋 What do we need?

Ingredients for marinated onions on a wooden board.
  • Red onion – of course! You can replace with red shallots too.
  • Red wine vinegar – I like these to help keep that vibrant pink colour in the onions, but you can replace with apple cider vinegar or white wine vinegar if you prefer.
  • Olive oil – I prefer to use regular olive oil, so it doesn’t overpower the flavour of the red onion, but you can use extra virgin olive oil if you really want that tangy-grassiness of extra virgin.
  • salt and oregano – to add extra flavour. The oregano makes the onions smell delicious too.

📺 Watch how to make it

Full recipe with detailed steps in the recipe card at the end of this post.

👩‍🍳PRO TIP These onions will last for longer if stored in the refrigerator, but the oil will solidify, so you’ll need to take them out of the fridge an hour or so before serving.

Overhead image of marinated sliced red onion in a glass bowl with a metal spoon sticking out.

🍽️ What to serve them with

How would you serve them? I’d love to hear in the comments below.

Side image of marinated sliced red onions in a glass jar with a metal spoon sticking out. The jar is on a vintage steel surface against a dark background.

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5 from 4 votes

Marinated Onions

Sliced red onions, marinated in red wine vinegar, olive oil and oregano make a fantastic side dish for salads and grilled meats. They're tangy, with a bit of crunch and a lovely silky coating.
Prep Time: 5 minutes
Total Time: 20 minutes
Servings: 8
Course: side dish
Cuisine: Greek


  • 1 red onion peeled and thinly sliced
  • ¼ tsp salt
  • 2 tbsp red wine vinegar
  • 6 tbsp olive oil
  • 1 tsp dried oregano


  • Add the sliced onions to a small bowl. Sprinkle over the salt and pour over the red wine vinegar. Stir together and put to one side for 15 minutes, giving it a stir a couple of times.
    1 red onion, ¼ tsp salt, 2 tbsp red wine vinegar
  • Add the olive oil and dried oregano and stir together.
    6 tbsp olive oil, 1 tsp dried oregano
  • Serve immediately or transfer to a clean air tight container to serve later (see storage information in notes section below).



Further enhance the flavour
You can marinate these onions for longer to develop flavours further. If marinading for longer, add the oil and oregano at the same time as the vinegar.
Place the mixture in a sealed container, such as a mason jar, and marinate for at least one hour.
They can be stored at room temperature, away from direct sunlight for 2-3 days. The flavour will continue to develop over this time.
If keeping for longer than a couple of days, store in the refrigerator instead (in a sealed container). They should keep for about 2 weeks.
The oil will solidify in the fridge, so you’ll need to remove from the fridge about 60-90 minutes before serving, to allow the oil to turn back to liquid.
Leftover oil
Don’t throw away the oil from the marinated onions! It makes a tasty salad dressing as it is.
If you want to add more flavour, add a pinch of salt and pepper and an extra splash of vinegar.
You could also add in extras such as honey, dijon mustard, chilli flakes if you like.
Nutritional information is approx, per serving (this recipe makes 8 servings).


Calories: 100kcal | Carbohydrates: 1g | Protein: 0.2g | Fat: 11g | Saturated Fat: 1g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Sodium: 74mg | Potassium: 25mg | Fiber: 0.3g | Sugar: 1g | Vitamin A: 5IU | Vitamin C: 1mg | Calcium: 8mg | Iron: 0.2mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Some of the links in this post may be affiliate links – which means if you buy the product I get a small commission (at no extra cost to you). If you do buy, then thank you! That’s what helps us to keep Kitchen Sanctuary running. The nutritional information provided is approximate and can vary depending on several factors. For more information please see our Terms & Conditions.

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Hi, I'm Nicky and I love to cook! I want to share with you my favourite, delicious family friendly recipes. I want to inspire you to create fantastic food for your family every day.

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  1. 5 stars
    I’ve hardly let this marinate and sampled it….so good already! Thank you for this recipe. I’ll also save the oil for making a dressing for salad as mentioned in the article.

  2. 5 stars
    Love the addition of oregano with the olive oil.
    I used them with cajun chicken and quinoa salad bowl 😋 Thinking Greek lamb next.

  3. 5 stars
    Marinated onions can you use white onion, instead of red onion, and white wine vinegar instead of red, looks very tasty, will try this.