Potato & Fennel Au Gratin

Potato & Fennel Au Gratin. 

The folks at Google really need to get on with making some sort of smell-0-vision for the internet so you can get the full cheesy, creamy, potato-y glory in this dish.

I know I’ve probably said it here before about some other gooey, cheesy potato thing, but this really is the best side dish I’ve ever made. Okay, maybe it’s tied with creamed spinach.

Things have been completely crazy around here. I’ve had friends in town, family in town, holiday concerts, regular concerts, and the Nutcracker. Yay for work! Because my family lives pretty spread out north, central, and south, they all decided to come here for an early Christmas celebration last week since I have the best weather. I also have the potato & fennel au gratin.

So we convened in sunny Florida, put up the tree, decked the halls, set the table with Grandma’s Christmas table cloth, and proceeded to have full on Christmas dinner of prime rib, brussels sproutsthis amazing chorizo stuffed date appetizer, a little wine, a little champagne, and these awesome au gratin potatoes.

Yes, with all that food, the potatoes stole the show. They’re that good. They’re also very easy to make!

Here’s what you need:


Russet Potatoes, Fennel, Onion, Olive Oil, Butter, Gruyere Cheese, Heavy Cream, Salt & Pepper.

Click here for a Potato & Fennel Au Gratin Shopping List

Preheat the oven to 350 degrees.

Fennel really transforms this dish from a plain old potato gratin. The fennel has a very, very slight anise flavor. Don’t let anyone tell you it tastes like licorice because it does not. I hate licorice and love fennel.

You’ll find these big unruly bulbs with greenery in your produce section. Cut off the top green parts and also the bottom stem end of the bulb.

Cut each bulb in half and use a sharp knife to cut the core out in a wedge.


You can save the green fronds for garnish or for using in salads. For this dish we only need the bulb.

Sometimes there is one outer layer of the bulb that is really hard and doesn’t look so great. If so, remove that layer and cut the fennel across the rounded top into thin strips.

Two small fennel bulbs (about the size of baseballs) should yield about 4 cups of sliced fennel.

While you’re slicing, cut an onion in half and into thin slices. One large onion should give you about 3 cups.


Heat 2 Tablespoons of olive oil in a large pan over medium heat.

Add the onions and fennel and sauté until tender and golden but not browned, about 15 minutes.


Take the sautéed fennel off the heat to cool slightly.


Meanwhile, peel 4 large russet potatoes. You absolutely want to use russet, or baking potatoes for this dish because they are firmer and will stand up to the long cooking time without getting mushy.

Use a mandolin or sharp knife to cut the potatoes into uniform slices about ¼ inch thick.


(Can you tell that these are not my hands? Probably not! That’s a little freaky.)

Place the sliced potatoes in a very large bowl and add 2 cups of heavy cream. No one said these are low cal…


Grate a ½ pound block (or slightly larger) of gruyere cheese and add 2 cups of cheese to the potatoes. Reserve ½ cup of cheese for the topping.


Add the sautéed fennel and onions and use your clean hands to toss it all together until thoroughly combined. Season with salt and pepper – about 1 teaspoon each.


Butter the inside of a large baking dish. This will take at least a 9×13 inch dish. If you have one with really deep sides, even better. My dish is actually 10×12 but the sides are 4 inches high so you can pack it full of potatoes.


Pour the potatoes into the buttered dish and use your hands to press them down and smooth out the top to create an even layer.


Add 2 Tablespoons of heavy cream to the reserved ½ cup of grated cheese.


“I like cream. I like cheese. I’m pretty sure I like prime rib too. When do we eat?”


Sprinkle the cheese and cream over the top of the potatoes. This will form the golden crust.


Bake at 350 degrees for 90 minutes until the top is golden and the potatoes are very tender.

Potato & Fennel Au Gratin

You can bake this ahead and reheat it later if you need your oven for turkey, ham, or the roast beast.

Luxurious is the best word to describe potato & fennel au gratin. Make them the star of your holiday meal or take them to a pot luck and make yourself the star!

Here’s the recipe – Adapted from Ina Garten The Barefoot Contessa Cookbook

Potato & Fennel Au Gratin

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9 Responses to “Potato & Fennel Au Gratin”

  1. gary rith says:

    oh MY CLAUDIA, such potato goodness 🙂 just linked to you at my blob and ……

  2. Use Wisdom says:

    My My My! I’m making these for Christmas dinner here too. Thank you!

  3. Busy Bee Suz says:

    Wow. This is just what I was looking for with our Christmas dinner! We are doing a standing rib roast (I think) And perhaps an entire grouper (I think) . I was going to do some sort of asparagus (bacon wrapped??) and I needed a nice starch too…..how many people do you think this serves?
    Looks just amazing!!!!

    • Suzanne, the recipe says 8 but we had 6 people and only had one serving leftover. Maybe we were extra piggy. It is very rich but also very delicious. Great leftover the next day too so I would say to go big…

  4. Trudie says:

    What a treat to find another recipe where fennel is an ingredient! I use it in salads and when roasting vegetables – but this is sooo nice!

  5. […] 10.) My friend Julie recently asked me to recommend a Mandoline Slicer and this was as close to the one that I use that I could find. Mandolines are SUPER sharp so you need to get one that is sturdy and also has the protective finger guard. Then you need to pledge to USE the finger guard every time. Those of you from Kansas City might find it funny that the box for my mandoline slicer still has a price tag from Function Junction that used to be on the Plaza on it. I’ve had it since college and it’s still going strong. If you get one from Santa, you should be sure to christen it by making Potato & Fennel Au Gratin! […]

  6. […] probably making a Corn, Zucchini & Spinach Gratin and good old creamy Potato & Fennel Au Gratin is always sooooo […]

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