Cajun-Style Slow Roasted Onions

This post may include affiliate links. Please read my disclaimer.ย 

Cajun Slow Roasted Onions in a teal cast iron skillet.

Want this recipe for deliciousness delivered to your inbox?

I'll email it to you so you can save it for later, and send you updates when I publish new recipes.

Soft and caramelized from the bottom up, my brand spanking new Cajun-style slow roasted onions are just as delicious as they are beautiful. Thick-sliced onions, sprinkled with salt, black pepper and cayenne. Topped with an herb and spice infused olive oil/butter mixture. Then, slow baked to soft, rich side dish rounds that literally melt in your mouth as they soothe your tired soul. Screaming loud yep and yay...

Cajun slow roasted onions on a round white plate.

Disclosure: A Sprinkling of Cayenne is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. 

This One's the Onion Side Dish of Champions, Y'all...

I always have one eye open for a 'something old' ingredient that I can cook into something brand spanking new. A few weeks ago, I challenged myself to make something totally new with a bag of carrots. So, I transformed them into cayenne maple glazed carrots. 

And, the experiment was soooo successful that I challenged myself to do it over again. I was fresh off of the victory heels of the carrot side dish that we've already eaten again since I posted the recipe. So, my confidence was high and my motivation was rock-solid. 

I walked around our humble kitchen analyzing ingredients. And suddenly my eyes fell upon a three-pound bag of onions. I usually use the onions for my roux, of course. Or, in any number of my original or re-created recipes with south Louisiana flair.

So, I suddenly found myself really, really ready to do something new with the onions. After much back and forth in my head, I decided to try my hand at creating a baked onions recipe. It had to have a nod to my south Louisiana motherland for sure. And, it had to be substantial enough to stand on its own as a side dish, as I was only going to serve it with roasted chicken and a tomato salad. 

I took my time planning out the Cajun-style slow roasted onions recipe. I used all of my favorite ingredients, and I exercised caution every step of the way, so that I wouldn't waste my time and my food. And neither would y'all. Yep.

And to tell y'all the truth, you can taste the restraint I used in every single bite of this dish. From the caramelized bottoms to the baked-in-herb tops to the soft-as-butta middle, these Cajun-style slow roasted onions are the stuff vegetable side dish dreams are made of!!

How to Make Cajun-Style Slow Roasted Onions

Start the Cajun-style slow roasted onions by preheating the oven to 300 degrees F. Then, peel the onions. And remove the tough outer flesh of each one. Trust me, you DON'T want to bite into that. It just won't cook down like the more tender inner onion flesh. So, take the extra step and go deeper down into the onion: 

A woman's hand holding an onion in her hand against a black background.

Then, lay the thick onions in an even layer along the bottom of your well-greased cast iron skillet, and season liberally with salt, black pepper and cayenne pepper: 

Seasoned sliced onions in a teal cast iron skillet.

Now, put celery, and red and green bell pepper pieces into your food processor. And give her a whirl: 

Celery and red and green bell peppers pulsed in a food processor.

Then pour the mixture into a large bowl. Add the remaining Cajun-style slow roasted onion flavoring ingredients into the bowl

Sauce Ingredients for Cajun slow roasted onions

And give it a good stir: 

Sauce ingredients in a white vintage Pyrex dish.

Then pour it over the seasoned onion slices. And pop it into the low temp oven:

Cajun roasted onions covered with sauce and ready to go into the oven.

And breathe in deeply, y'all!! Cause the escaping oven aromas are going to have you straight beside yourself before you know it. Yep. It slowly creeps a little at a time. A faint oniony-pepper whiff here. A buttery-parsley smell tease there. Then, as the Cajun-style slow roasted onions get close to optimal doneness, the deep, rich caramelization bits release their essence. 

So, it's all you can do to wait another second before they're all done!!! Yay!!

But, once you taste the deep, caramelized flavor bombs and the literal melt-in-your-mouth, almost candy-like texture, you'll know that these beauties were definitely worth the wait. Richly seasoned with a tantalizing cayenne backbite, these best ever onion side dish are certainly company and holiday party-worthy. Yep, but they're so easy and addictively satisfying that they're worth the two-person dinner effort any day of the week. 

Share these Cajun-style slow roasted onions with those who'll taste your pure, sweet love for them in every low-and-slow, sassy bite. And see y'all on the yum side...

Square shot of Cajun-Style Slow Roasted Onions

Cajun Slow Roasted Onions in a teal cast iron skillet.

Cajun-Style Slow Roasted Onions

Fresh onion slices arranged in a cast iron skillet, then topped with an herb and spice-infused olive oil butter sauce. Slow baked until the middle is soft, and the tops and bottoms are caramelized.
Print Pin Rate
Course: Appetizer/ Side Dish
Cuisine: Cajun
Keyword: baked onions, cajun onions, cajun slow roasted onions, roasted onions, slow roasted onions
Prep Time: 20 minutes
Cook Time: 1 hour 30 minutes
Servings: 2 people
Calories: 499kcal
Author: Lyn Corinne Liner

Ingredients

  • 3 to 4 yellow onions enough to cover the bottom of the pan when cut into circles, see instructions
  • ยผ red bell pepper, cut into strips
  • ยผ green bell pepper, cut into strips
  • 1 celery rib, trimmed
  • โ…“ cup olive oil
  • 2 tablespoons melted butter
  • 1 tablespoon minced garlic
  • 1 teaspoon Louisiana hot sauce
  • ยผ teaspoon liquid smoke
  • 1 tablespoon fresh parsley leaves, minced
  • 1 tablespoon fresh celery leaves, minced, optional
  • salt, black pepper and cayenne pepper to taste

Instructions

  • Preheat the oven to 300 degrees F.
  • Peel the onions, then remove the outer edges of each onion's flesh. See post.
  • Cut each onion into thick circular slices. Arrange onion slices in a single layer in a well-greased enameled cast iron skillet.
  • Sprinkle the slices liberally with salt, black pepper and cayenne pepper.
  • Place the red and green bell pepper strips and the celery rib into the bowl of your food processor. Pulse the mixture until finely chopped, then pour into a large bowl.
  • Pour the remaining ingredients into the bowl with the minced veggies.
  • Stir until well-combined.
  • Pour the mixture evenly over the onion slices in the skillet.
  • Bake uncovered for 1 ยผ to 1 ยฝ hours, using a spoon to pour the olive oil/butter herb mixture that falls into the bottom of the pan over the onions approximatley every 20 minutes.
  • Let cool for 5 minutes before serving.

Notes

You can substitute white onions in place of the yellow onions, but not red onions as the recipe just won't turn out the same.
 
Click here to follow on Pinterest @asprinklingofcayenne

The information shown is an estimate provided by a third-party, online computer-generated nutrition calculator, not a registered dietitian or certified nutritionist. Actual nutritional content will vary based upon brands used, measuring methods and individual portion sizes, along with other factors.

See our full nutrition disclaimer here.

Nutrition

Calories: 499kcal | Carbohydrates: 19g | Protein: 3g | Fat: 48g | Saturated Fat: 12g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 29g | Trans Fat: 0.5g | Cholesterol: 30mg | Sodium: 156mg | Potassium: 337mg | Fiber: 4g | Sugar: 8g | Vitamin A: 1055IU | Vitamin C: 49mg | Calcium: 55mg | Iron: 1mg

Cajun Style Slow Roasted Onions Pinterest Pin

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating




This site uses Akismet to reduce spam. Learn how your comment data is processed.