Makes 1/3 cup | Prep Time: 10 minutes / Cook Time: 40 minutes
Sweet, savory, tangy, and packed with flavor, these small batch caramelized onions are finished with a little Dijon mustard, brown sugar, and balsamic vinegar for incredible added flavor. They’re the perfect topping for melts, burgers, grain bowls, or fancy grilled cheese.
These aren’t your average caramelized onions. They’re deeply golden, rich, and just a little sharp from the Dijon mustard and balsamic vinegar. Adding just a little bit of both (and some brown sugar!) creates a jammy, savory-sweet condiment that elevates anything it touches.
This small batch version uses just one yellow onion and makes about 1/3 cup of caramelized onions, which is perfect for a couple of Grilled Ham and Cheese Sandwiches, burgers, or stirred into some scrambled eggs in the morning. The recipe takes about 50 minutes total, but it’s easy, I promise! They store well, reheat beautifully, and honestly… they’re kind of addictive.
Ingredients
- 1 medium/large Yellow Onion (about 2½ cups thinly sliced)
- 1 tbsp. Unsalted Butter
- 1 tsp. Olive Oil
- 1/2 tsp. Kosher Salt
- 1/2 tsp. Dijon Mustard
- 1/2 tsp. Brown Sugar
- 1/2 tsp. Balsamic Vinegar
Ingredient Notes & FAQs
- Yellow Onion: Yellow onions have a higher sugar content than white or red onions, so I find them to be ideal for caramelizing! Note that yellow onions are NOT sweet onions. Sweet onions (like Vidalia onions) work well, too – they’ll just have a sweeter flavor.
- Why Butter AND Olive Oil?: The butter is there for flavor, but it can brown too quickly because it’s sensitive to heat. Olive oil helps stabilize the butter and prevent it from burning.
- Salt: I always use Diamond Crystal Kosher Salt for every recipe. I actually tested these with 1 teaspoon of that salt, and loved them. However, I know a lot of people are salt sensitive. I recommend using the amount that feels right to you. If you’re using a fine sea salt, reduce the amount to 1/4 teaspoon if you’re nervous about the amount.
- Dijon Mustard: I just used Koop’s (as you can see in the photo), but any brand is great! A champagne mustard would be gorgeous in this, too.
- Balsamic Vinegar: Balsamic vinegar is one of those ingredients where quality matters. A small (yet expensive) bottle of balsamic vinegar may seem like an investment up front, but it will last you a loooong time. And the flavor is usually richer, sweeter, and worth the splurge! I do not recommend using any other type of vinegar in this recipe. Stick with balsamic.
This recipe is small batch by design, but it can easily be doubled or tripled if needed. These will keep in the refrigerator for a week, or you can freeze them for up to three months.
Directions
Step One: Slice the Onions. Cut the root and stem end off of the onion. Peel the papery outer layer, then set the onion on the cutting board, one of the flat sides down so it doesn’t roll around. Slice the onion in half, then place both halves flat side down. Thinly slice the onion along its natural lines, making the slices as even as possible so they cook evenly. (The slices should be about 1/8″ thick.)
Step Two: Melt the Butter + Olive Oil. In a medium skillet (I use an 8″ stainless steel skillet – a nonstick skillet would be perfect, too!), melt the butter and olive oil over medium heat.
Step Three: Cook the Onions. Add the onions to the hot skillet, and sprinkle with salt. Stir to coat the onions in fat and salt, then let them cook over medium heat for about five minutes.
Step Four: Stir + Cook until Caramelized. Stir the onions around, then turn the heat down to medium-low. Continue cooking them for about 30 minutes, stirring them every five minutes, until they’re deeply golden brown and very soft.
Step Five: Add Flavor. Stir the Dijon mustard, brown sugar, and balsamic vinegar into the onions until totally combined. Cook for another 2-3 minutes, then remove them from the heat and allow them to slightly cool. Use immediately or store in an airtight container in the refrigerator for up to a week!
Recipe Tips & Tricks
- Even Slices: Slice your onion thin and as evenly as possible. It will cook at the same rate, which creates the best consistency!
- Don’t Turn up the Heat: You may be tempted to rush the process and turn the heat up: don’t. This is a low and slow process, so grab a glass of wine and just roll with it. 🙂
- Don’t Stir Constantly: You may also be tempted to stir these a lot. Don’t do that either! They develop their color as they sit with the heat, so just let them chill. If you have the urge to stir every three minutes or so, that’s okay. But give them some time to just hang out directly in the pan, too.
Ways to Use these Onions
- On this delicious Grilled Ham and Cheese Melt
- On top of burgers or sliders
- Stirred into scrambled eggs or omelets
- On top of flatbreads or pizzas
- Mixed into a grain bowl
- Chopped and tossed into salads
Just FYI, my entire website is packed with small batch recipes! If you’re often cooking for one or two people, feel free to sign up for my weekly newsletter. I only send one newsletter each week, but it’s packed with four small batch recipes, as well as a few tips and tricks for you.
How to Store
- Store in the Refrigerator: Let the onions cool, then transfer to an airtight container. Store in the fridge for up to a week. Reheat gently in a skillet or microwave to bring them back to life. You can also store these in the freezer for up to three months.
More Small Batch Broccoli + Orzo Favorites
- The best Roasted Vegetable Pasta with Parmesan Cream Sauce (makes 2-3 servings)
- New! Garlicky Lemon Orzo (makes 2 servings)
- Fan Favorite Spicy Cheddar Chicken + Broccoli Ozo (makes 2 servings)
- Feeling fancy? Roasted Broccoli + Cheddar Risotto is fiiiire! (makes 2 servings)
- Veggie-packed Cajun Chicken Orzo with Spinach (makes 2-3 servings)
I’m so excited for you try these caramelized balsamic Dijon onions! It may be hard to go back to plain ones after you do! 🤣 They’re easy, flavor-packed, and somehow make any basic sandwich feel like something from your favorite lunch spot. Make a batch, give them a quick taste test, and prepare to start adding them to everything. If you want to make more than two servings, there is a little slider bar in the recipe card below (near “servings”). Slide that bar to adjust the amount you want to make, and the ingredients will automatically adjust for you!
If you make this recipe and love it, please leave a comment and / or star rating below! You can also share it on Instagram and tag me so we can connect and be *friends*! Also, if you have any questions about the ingredients or how to make it, send me an email so I can help out.
xx Sara
Small Batch Balsamic Dijon Caramelized Onions
Ingredients
- 1 medium Yellow Onion (about 2 1/2 cups thinly sliced)
- 1 tbsp. Unsalted Butter
- 1 tsp. Olive Oil
- 1/2 tsp. Kosher Salt
- 1/2 tsp. Dijon Mustard
- 1/2 tsp. Light Brown Sugar
- 1/2 tsp. Balsamic Vinegar
Instructions
- Slice the Onions. Cut the root and stem end off of the onion. Peel the papery outer layer, then set the onion on the cutting board, one of the flat sides down so it doesn’t roll around. Slice the onion in half, then place both halves flat side down. Thinly slice the onion along its natural lines, making the slices as even as possible so they cook evenly. (The slices should be about 1/8″ thick.)
- Melt the Butter + Olive Oil. In a medium skillet (I use an 8″ stainless steel skillet – a nonstick skillet would be perfect, too!), melt the butter and olive oil over medium heat.
- Cook the Onions. Add the onions to the hot skillet, and sprinkle with salt. Stir to coat the onions in fat and salt, then let them cook over medium heat for about five minutes.
- Stir + Cook until Caramelized. Stir the onions around, then turn the heat down to medium-low. Continue cooking them for about 30 minutes, stirring them every five minutes, until they’re deeply golden brown and very soft.
- Add Flavor. Stir the Dijon mustard, brown sugar, and balsamic vinegar into the onions until totally combined. Cook for another 2-3 minutes, then remove them from the heat and allow them to slightly cool. Use immediately or store in an airtight container in the refrigerator for up to a week!
Notes
- Yellow Onion: Yellow onions have a higher sugar content than white or red onions, so I find them to be ideal for caramelizing! Note that yellow onions are NOT sweet onions. Sweet onions (like Vidalia onions) work well, too – they’ll just have a sweeter flavor. Slice your onion thin and as evenly as possible. It will cook at the same rate, which creates the best consistency!
- Don’t Turn up the Heat: You may be tempted to rush the process and turn the heat up: don’t. This is a low and slow process, so grab a glass of wine and just roll with it. 🙂
Nutrition
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