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These Grilled Onions are sweet, tender, and lightly charred around the edges. Made with just onions, oil, salt, and pepper, they’re an easy side dish for grilled meats, burgers, sandwiches, and more.
As a certified nutrition coach, I love simple vegetable recipes that taste great without a long list of ingredients. These grilled onions are one of my favorite ways to prepare onions because grilling brings out their natural sweetness while adding a delicious smoky flavor. They’re easy enough for a weeknight dinner side dish and perfect for summer cookouts.
Why You’ll Love These Grilled Onions
I am so lucky that all five of my 5 kids love grilled onions. I make them all the time because they pair well with just about anything. Here’s why I think you will love them too.
- They are easy to make with just a few ingredients
- Naturally sweet and savory
- Tender in the middle with lightly charred edges.
- Ready in about 15 minutes
- They are perfect on burgers, steaks, chicken, and sandwiches
- Can be made on an outdoor grill or grill pan
- An easy way to add more vegetables to your meal
Key Ingredients
Below are the key ingredients for making grilled onions. The full recipe and step-by-step instructions are found in the recipe card.
- Sweet Onions: I recommend large sweet onions, such as Vidalia or Walla Walla. Their natural sweetness becomes even more intense as they cook on the grill.
- Olive or Avocado Oil: A little oil helps the onions brown and keeps them from sticking to the grill. Either olive oil or avocado oil works well.
- Kosher Salt and Black Pepper: Simple seasoning is all you need. The grill adds plenty of smoky flavor, while the salt and pepper bring out the onions’ natural sweetness.
What Type of Onion Is Best for Grilling?
Large sweet onions are my favorite for grilling. Vidalia and Walla Walla onions work especially well because they soften and caramelize as they cook.
You can also use yellow onions if you prefer a stronger onion flavor. Red onions are another good option and will have a slightly sharper, more savory flavor.
Recipe Overview
How To Make Grilled Onions
Prepare the Grill: Preheat an outdoor grill or grill pan over high heat. Once hot, reduce the heat to medium before adding the onions.
Prepare the Onions: Peel the onions carefully, keeping them intact so they are easier to slice into slabs. Rinse and pat them dry.
Trim the root end, then place each onion on a cutting board. Using a sharp knife, carefully slice the onions into ¾- to 1-inch-thick slabs.
Season the Onions: Brush both sides of each onion slice with olive oil or avocado oil. Season both sides with kosher salt and black pepper.
Grill the Onions: Place the onion slabs on the grill over medium heat. Cook for about 5–6 minutes per side, or until the onions are tender and have beautiful char marks.
Carefully remove the onions from the grill and serve warm.
Tips for the Best Grilled Onions
Keep the Onion Slices Thick: Don’t slice the onions too thin. Thicker slabs are easier to flip and are less likely to fall apart on the grill.
Leave the Root End Intact While Slicing: If possible, keep the root end intact while slicing the onion. This helps hold the layers together while you’re grilling. You can trim it after slicing if needed.
Use a Sharp Knife: A sharp knife makes it much easier to cut clean, even slices without crushing the onion.
Don’t Move the Onions Too Much: Once the onions are on the grill, leave them alone while they cook. This gives them time to develop those beautiful char marks.
Watch the Heat: If the onions are browning too quickly but aren’t tender yet, reduce the heat. You want them to soften while developing a golden, lightly charred exterior.
Use a Wide Spatula: A wide spatula makes it much easier to flip the onion slabs without breaking them apart.
How Do You Keep Grilled Onions From Falling Apart?
The easiest way is to cut the onions into ¾- to 1-inch thick slabs and handle them gently when flipping.
You can also leave the root end intact while slicing. The layers will stay connected while the onion cooks, making it easier to turn on the grill.
As the onions become tender, they may naturally separate into layers. That’s completely fine and is part of what makes grilled onions so good.
Can I Make Grilled Onions on a Grill Pan?
Yes. A grill pan works very well when you don’t have access to an outdoor grill.
Preheat the grill pan over medium to medium-high heat, lightly oil the onions, and cook them for about 5 to 6 minutes per side, or until tender and nicely charred.
A grill pan may not give you exactly the same smoky flavor as an outdoor grill, but you’ll still get some nice grill marks and caramelized edges.
Flavor Variations
The basic salt and pepper seasoning is delicious, but you can easily change up the flavor.
- Garlic Herb: Add garlic powder and a sprinkle of dried Italian seasoning before grilling.
- Balsamic: Brush the grilled onions with a little balsamic vinegar during the last minute of cooking.
- Parmesan: Sprinkle finely grated Parmesan over the onions right after grilling.
- Spicy: Add a pinch of crushed red pepper flakes or cayenne with the salt and pepper.
- Fresh Herbs: Finish the onions with chopped fresh parsley, chives, or thyme before serving.
- Steakhouse Style: Finish with a little butter, fresh parsley, and cracked black pepper for a richer side dish.
What to Serve With Grilled Onions
Grilled onions are so versatile and pair well with almost any grilled meal. Try them with:
- Grilled chicken like this grilled chicken kafta
- Grilled Chimichurri steak
- Add them to Hamburgers
- Grilled salmon
- Grilled shrimp
- Chicken Cutlet sandwiches
You can also chop leftover grilled onions and add them to wraps, grain bowls, tacos, or salads.
Common Questions
Yes. Grilled onions can be made a day or two ahead and reheated when you’re ready to serve them.
Absolutely. Red onions have a stronger flavor but become sweeter and more tender when grilled.
The grill may be too hot. Reduce the heat to medium and allow the onions to cook more slowly so the inside has time to become tender.
Yes, but whole onions take considerably longer to cook. For this recipe, slicing the onions into thick slabs allows them to cook much faster while still developing a nice char
Common Mistakes to Avoid
- Cutting the Onions Too Thin: Thin slices cook too quickly and are harder to flip. Stick with thicker slabs.
- Using Too Much Oil: You only need enough oil to lightly coat the onions. Too much can cause flare-ups on an outdoor grill.
- Grilling Over High Heat the Entire Time: High heat can char the outside before the inside becomes tender. Medium heat gives the onions time to soften while they brown.
- Flipping Too Often: Let the onions cook undisturbed so they can develop good grill marks.
- Trying to Flip Them With Tongs: Tongs can squeeze and break the soft onion layers. A wide spatula is easier to use.
Storage
- Store leftover grilled onions in an airtight container in the refrigerator for up to 4 days.
- Reheat them gently in a skillet, on the grill, or in the microwave until warmed through.
- You can also enjoy them cold or at room temperature in salads, sandwiches, and wraps.
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Thank you so much for being here and for cooking along with me. If you try this recipe, I’d love to hear how it turned out. Leave a comment and ⭐️ rating below.
Grilled Onions Recipe
Ingredients
- 3 large sweet onions, peeled- like Walla Walla or Vidalia
- 1 tablespoon avocado oil, or olive oil
- 1 teaspoon kosher salt
- Ground pepper, to taste
Instructions
- Preheat an oven-safe skillet or outdoor grill over high heat.
- In the meantime. Carefully peel the 3 large sweet onions so you don’t cut through the outer layer. Rinse the onions.
- Trim the onion roots and slice carefully.
- On a cutting board, use a sharp knife to cut the onions into ¾- to 1-inch-thick slabs.
- Next, brush each side of the sliced onions with 1 tablespoon avocado oil. Sprinkle each side with 1 teaspoon kosher salt and Ground pepper.
- Grill the onions over medium heat for 5-6 minutes per side, until charred and soft.
Notes
- Serving Size: ½ large grilled onion
- Use large sweet onions such as Vidalia or Walla Walla for the best flavor.
- Cut the onions into thick ¾- to 1-inch slabs so they hold together on the grill.
- Keep the root end intact while slicing to help the onion layers stay together.
- Use a wide spatula to carefully flip the onions.
- Cook over medium heat so the onions have time to become tender without burning.
- Grilled onions are best served warm but can also be enjoyed at room temperature.
- Store leftovers in an airtight container in the refrigerator for up to 4 days.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
