Caramelized Onion Butter
This caramelized onion butter is a must-have for your holiday table. Onions cook low and slow in butter and olive oil until deep amber, jammy and sweet, then get mashed into softened butter with salt, pepper and fresh thyme. Spread this onion butter on warm rolls, steak, roasted veggies or mashed potatoes.
Love caramelized onions? Try my Caramelized Onion Grilled Cheese.
Why You’ll Love This Caramelized Onion Butter
- Rich, sweet and savory.
- Only 8 ingredients.
- Makes everything better, from rolls to steak.
- Make-ahead friendly.
Ingredients for Caramelized Onion Butter
The Caramelized Onions
A large yellow onion, butter, olive oil and a pinch of salt.
The Butter
Softened unsalted butter, kosher salt, black pepper and fresh thyme.
Dietary note: This compound butter is vegetarian and gluten free.
How to Make Caramelized Onion Butter
Step 1: Start the onions
Heat butter and oil in a wide pan over medium-low. Add the onions, stir to coat and spread evenly.
Step 2: Soften
Cook slowly 15 to 20 minutes, stirring every few minutes, until soft and translucent.
Step 3: Caramelize
Add salt, lower the heat slightly and cook 30 to 45 minutes more, letting them sit between stirs. Deglaze with 1 to 2 tablespoons water as needed.
Step 4: Cool
Cook until deep amber and jammy, then cool completely.
Step 5: Make the butter
Mash the onions into softened butter with salt, pepper and thyme until smooth.
Carly’s Expert Tips
- Low and slow is the secret to jammy onions.
- Deglaze with water to prevent sticking.
- Cool the onions before mixing so the butter does not melt.
- Chop the onions finely for a smoother butter.
Make It Your Own
- Garlic: Add roasted garlic.
- Balsamic: Add a splash of balsamic to the onions.
- Herbs: Use rosemary or sage.
- Honey: Add a drizzle of honey.
Make-Ahead and Meal Prep: Make up to 1 week ahead, or roll into a log and freeze for up to 3 months.
What to Serve With Caramelized Onion Butter
Spread on warm dinner rolls, melt over steak, toss with roasted veggies or stir into mashed potatoes.
Storing and Reheating
Store in the fridge for up to 1 week.
Freeze for up to 3 months.
What People Ask About Caramelized Onion Butter
Can I use a different onion?
Yes, but yellow onions are sweetest.
How long does it take to caramelize onions?
About 45 minutes to 1 hour.
Can I freeze onion butter?
Yes, for up to 3 months.
What do you use caramelized onion butter on?
Rolls, steak, veggies and mashed potatoes.
Caramelized Onion Butter
Ingredients
Method
- Mash caramelized onions into softened butter with salt, pepper, and thyme until smooth.
- Heat butter and oil in a wide pan over medium-low until melted.
- Add onions, stir to coat, and spread evenly.
- Cook slowly for 15–20 minutes, stirring every few minutes, until soft and translucent.
- Add salt and lower heat slightly. Continue cooking for 30–45 minutes, letting onions sit between stirs for deep caramelization. Deglaze with 1–2 tbsp water as needed to prevent sticking.
- Onions are done when deep amber, jammy, and sweet. Taste and adjust salt; add pepper at the end if desired.
Nutrition
Notes
- Deglaze the pan with a small amount of water to prevent onions from sticking and burning.
- Use fresh thyme for the best flavor in the butter.
- Let the onions caramelize slowly for the richest taste.
