Caramelized Fennel and Onions

Sliced onions and fennel, slowly cooked until lightly browned, tossed with Parmesan, lemon, and parsley.

By
Elise Bauer
Elise Bauer
Elise Bauer
Elise founded Simply Recipes in 2003 and led the site until 2019. She has an MA in Food Research from Stanford University.
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Updated September 10, 2023
Elise Bauer
Caramelized Fennel and Onions
Elise Bauer

Fennel lovers, onion lovers, unite!

And then take a shower in grated Parmesan, lemon zest, and chopped parsley.

I'd like to say this is quick and easy, but it's not quick. It's long and easy, the sort of thing you can just put on the stove and give a stir every once in a while, as you cook the rest of the meal.

The onions and fennel are only lightly caramelized. You could cook them longer if you wanted, or sprinkle some sugar on them to bring out more of the caramelization.

But just cooking them down and lightly browning them, and then tossing them with everything else, works for me. Wonderful flavors. Terrific alongside grilled fish or chicken.

Caramelized Fennel and Onions

Prep Time 10 mins
Cook Time 60 mins
Total Time 70 mins
Servings 4 servings

Ingredients

  • 2 large onions, halved then sliced lengthwise (root to tip) in 1/4-inch-thick slices

  • 2 large fennel bulbs, sliced into 1/4-inch-thick slices

  • 1/4 cup extra virgin olive oil

  • 1 tablespoon butter

  • Salt

  • 1/4 cup grated Parmesan

  • 2 tablespoons chopped fresh parsley

  • 1 teaspoon lemon zest

  • 2 teaspoons lemon juice

Method

  1. Cook fennel and onions in olive oil and butter:

    Heat olive oil and butter in a large, uncovered, wide pan on medium high heat. Add the sliced fennel and onions and stir to coat. Stir occasionally.

    After about 10 minutes, sprinkle the onions and fennel with salt. Lower the temperature to medium.

    You want to strike a balance between allowing the pan to get hot enough so that some caramelization (when the natural sugars in the onion and fennel start to brown) and keeping the pot from getting so hot that the onions and fennel dry out.

    If it becomes an issue, you can add a couple tablespoons of water to the pan to help the onions and fennel to keep from drying out too much.

  2. Scrape up browned bits:

    Stir occasionally, scraping up any browned bits from the bottom of the pan. Note that the browned bits are the tastiest parts.

    Cook for another 30 minutes to an hour, depending on how much of a hurry you're in, and how caramelized you want your mixture to be. The longer you cook, the more caramelized and browned.

    Taste test along the way to see if the cooking has been sufficient for your taste.

    By the way, the onions and fennel will have plenty of flavor without having to be completely cooked down and browned all over.

  3. Toss with Parmesan, parsley, lemon:

    When ready to serve, remove from heat and toss in the freshly grated Parmesan cheese, the chopped parsley, lemon zest and lemon juice. Taste and add more lemon juice if necessary.

    Serve alone as a side to chicken or seafood, or on crackers or thinly sliced toasted baguette for a crostini. You can also use it as a filling for a rustic tart.

Links:

How to Slice an Onion

Nutrition Facts (per serving)
214 Calories
18g Fat
11g Carbs
3g Protein
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Nutrition Facts
Servings: 4
Amount per serving
Calories 214
% Daily Value*
Total Fat 18g 24%
Saturated Fat 5g 24%
Cholesterol 13mg 4%
Sodium 307mg 13%
Total Carbohydrate 11g 4%
Dietary Fiber 2g 8%
Total Sugars 5g
Protein 3g
Vitamin C 12mg 60%
Calcium 93mg 7%
Iron 1mg 4%
Potassium 313mg 7%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.