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Whole30 + Keto Marinated Onions

  • Author: Natalie
  • Prep Time: 5 minutes
  • Cook Time: 12 hours
  • Total Time: 12 hours 5 minutes
  • Yield: 6 1x


Recipe heavily inspired by No Crumbs Left, who is one of my favorite food bloggers to follow!




  1. Place the sliced onions in a No Crumbs Left Marinated Onion Bowl. (I highly recommend getting a Marinated Onion Bowl! Holds the onions perfectly, has a pour spout so you can easily pour the onion marinade, and is such a gorgeous piece of pottery!)
  2. In a measuring cup, combine the olive oil, red wine vinegar, oregano and salt. Stir to combine.
  3. Pour the marinade over the onions. All the onions should be covered.
  4. Let it sit on your counter for at least 12 hours.
  5. Will keep for at least 5 days on the counter.


I don’t recommend storing these in the refrigerator. The oil solidifies. If you’re getting past the 5 days, you could store in a mason jar and refrigerate. You’ll just have to bring them to room temperature when you want to eat them again.

These are really best with red onions, but you could use a yellow onion if that’s all you have.

Dried oregano is much better than fresh oregano for these onions

You don’t want to reuse the marinade. It gets too potent of an onion flavor. You’ll want to start with a fresh marinade each time you make them.