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5 from 8 ratings

Whole30 + Keto Marinated Onions

Recipe heavily inspired by
, who is one of my favorite food bloggers to follow!
This Whole30 + Keto Marinated Onions Recipe is a simple low carb, healthy fat macros side dish and marinade that adds tons of flavor to almost every recipe!
Prep Time5 mins
Cook Time12 hrs
Total Time12 hrs 5 mins
Course: Condiment, Side Dish
Cuisine: American
Servings: 6
Calories: 190
Author: Natalie


  • 1 medium red onion sliced 1/4" thick (I love using my mandoline)
  • 3/4 cup olive oil
  • 1/4 cup red wine vinegar
  • 1 tablespoon dried oregano
  • 1 teaspoon kosher salt


  • 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!)
  • In a measuring cup, combine the olive oil, red wine vinegar, oregano and salt. Stir to combine.
  • Pour the marinade over the onions. All the onions should be covered.
  • Let it sit on your counter for at least 12 hours.
  • 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.


Calories: 190 | Total Carbs: 2.1g | Protein: 0.3g | Fat: 21g | Fiber: 0.5g | Net Carbs: 2g