Scalloped Potato Kale Gratin
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This creamy scalloped potatoes recipe is a potato kale bake that features layers of thinly sliced potatoes, a reduced cream sauce, plus tender sauteed leeks and kale. It’s a rich and hearty side dish perfect for Thanksgiving, Easter, or Christmas, or to serve as a part of a comforting family meal.
I love potatoes. All varieties, all the ways to eat them – creamy garlic thyme mashed potatoes, french fries, skillet lemon potatoes, oven roasted baby potatoes – they’re just so versatile and delicious! But, one of my all time favorite ways to have potatoes is in a super creamy scalloped potato dish like this potato kale bake.
This particular version was first inspired by a popular Irish potato dish colcannon around St. Patrick’s day. It’s typically mashed potatoes that are mixed with kale or cabbage and leeks, or onion. Those flavors translate so well into other recipes like Colcannon inspired twice baked potatoes, and this creamy layered potato bake. We love it so much, it’s a family favorite with our smoked corned beef brisket, but also as a Thanksgiving or holiday side dish.
Recipe Features
- You’ll only need 4 additional ingredients aside from salt, pepper, and butter to make this.
- It has the richest, most delicious sauce thanks to the par-boiling and reduction steps in the beginning.
- It’s hearty and can easily serve 8 or more as a side to other dishes.
- Make it ahead by assembling the kale potato bake entirely, then refrigerating it and baking it the next day.
Scalloped vs. Gratin
You can search the internet and find warring definitions of what makes something a scalloped potato or a gratin, and sometimes, a dish can even be both. The debate centers around whether it has to have cheese in it, on top of it, or if it should have a buttered breadcrumb topping.
I say scalloped refers to the thin slices. A gratin is a baked dish that has been caramelized on the top, that might be from cream, cheese, breadcrumbs, or all of the above. Chef Tom Colicchio (one of my go to references), calls the technique I use in this dish a gratin, so that’s my story and I’m sticking to it.
Fun fact, you can cook almost any vegetable ‘au gratin’. It’s just a cooking technique consisting of thinly sliced layered vegetables with cream, breadcrumbs, or cheese (or all of them) and baked until browned on top. Broccoli, leeks, or a delicious roasted cauliflower and gruyere gratin are just a few suggestions.
Ingredients and Substitutions
Since this was inspired by colcannon, I thought I’d keep the ingredient list fairly similar and simple to that style of mashed potato. If you choose to add cheese or breadcrumbs, you do you, make it how you like it! I’ve shared my suggestions on how to do so below.
- Potatoes – I use russet, which are a high starch potato that are delicious with cream. It takes about 2 medium to large potatoes. Red or white waxy potatoes also work.
- Heavy Cream – This is necessary and I do not recommend swapping it with anything else.
- Kale – Any variety of kale, or other hearty green like swiss chard or collard greens also works.
- Leeks – Choose leeks with the most white for the tenderest result. Shallots work well as a replacement.
- Salt & Pepper – These are certainly necessary in an otherwise simple dish to make it taste good!
- Butter – Unsalted so you can season the leeks yourself.
Optional Ingredients:
- Parsley – If I have it, I chop it and sprinkle it over the final dish.
- Cheese – Feel free to mix 1/4-1/2 cup of freshy shredded aged cheese into the cream, and to sprinkle more on top as desired. Parmesan, Asiago, or Romano are all delicious. Do not use pre-shredded options, as they don’t melt well.
- Breadcrumbs – If you need that crunchy topping, mix 1 cup of plain purchased or homemade bread crumbs with 2 tablespoons of melted butter. Sprinkle over the top before baking.
Step by Step Instructions
This is a big potato kale gratin, easily serving a group of 6 to 8, possibly more! You can also half it easily if you’d like. It’s an excellent make ahead side dish that you can prep and pop in the oven the next day to bake.
Step 1 – Prep Ingredients
Wash and cut the kale, leeks, and potatoes. The kale needs a rough chop, the leeks do best as half-moons, and the potatoes need to be consistently and thinly sliced. A mandolin slicer is the best tool for the job, but a careful knife will also work.
Bonus tip: Leeks must be washed thoroughly because they harbor dirt between the layers. Slice them in half lengthwise, then slice into half moons and add them to a bowl of cool water. Gently swish them and the dirt will sink to the bottom. Use a spider strainer or your hands to gently scoop leeks from the top of the water (they float). Discard the water. Use a salad spinner to rid both the leeks and the kale of excess water.
Step 2 – Cook the Components
Combine the salt, potatoes, and cream in a sauce pan. Simmer rapidly until the potatoes are just barely fork tender. Do not cook them too much at this step. Strain the potatoes out and spread them out to cool. Make sure you catch the strained cream in a bowl. Return the cream to the pan and reduce by half. Season with more salt as needed after it’s reduced.
While the cream is reducing, sauté the leeks in a tablespoon of oil or butter over medium heat, stirring often. After 8-10 minutes, the leeks will be tender. Add the kale and sauté until it has reduced down and become tender.
Step 3 – Layer and Bake
Preheat your oven to 375°F and get your cooked ingredients ready to layer into a large 9×13 casserole dish.
Layer half the potatoes on the bottom then top it with the entire kale and leek mixture. Pour over half the cream, then layer the remaining potatoes on top. Pour over remaining cream and add any cheese or breadcrumbs if you’re using them.
Bake uncovered for 25 minutes, or until the top is bubbling and browning. Remove and let stand for 10-15 minutes, then serve. We love it with dishes like Dr. Pepper Short Ribs, Ras el Hanout Chicken, Cast Iron Salmon, and Lemon Artichoke Chicken. Store leftover potato kale gratin in the fridge for up to 3 days.
FAQs
I don’t recommend freezing cream based dishes like this kale potato bake. The cream separates when thawed and creates an unpleasant texture.
The use of high fat cream, like heavy cream, is the key to a thickened final dish. As it reduces in the pot before baking it will get really thick and then as it bakes it will thicken further to a dense sauce.
Because the thickening technique I do not recommend simply substituting a low fat, or non-dairy milk because it is more likely to break or curdle. Instead, try this Vegan Scalloped Potatoes from Nora Cooks, designed for those types of milks.
A common cause of a curdled dairy based sauce is too high of a heat or low fat dairy. Heavy cream, due to the high fat content, prevents that, but avoid the highest setting on your burners, and the temptation to crank the oven up for quicker cooking.
Assemble the gratin entirely, then cover and place in the refrigerator for up to 24 hours. Then bake as directed, but add 10 extra minutes to the bake time since it’s coming out of the fridge cold.
Whatever you choose to serve this with and whoever you decide to share this, you’ll be more than happy! I sincerely hope you enjoy this super creamy, simple potato kale bake. Check out my other delicious side dishes while you’re here!
Love this recipe? Please consider leaving a 5 star rating in the recipe card below, or a comment to share your experience with fellow home cooks. I hope you enjoy and as always, Happy Eating!
Creamy Scalloped Potato Kale Gratin
Ingredients
- 2 large russet potatoes or 3 lbs potatoes
- 2 C leeks about 1 leek
- 1 bunch kale
- 4 C heavy cream
- 2 Tbs butter or oil
- Salt & Pepper to taste
- 2 Tbs parsley optional
Instructions
- Preheat oven to 375°F.
- Peel and thinly slice potatoes on mandoline, or by hand carefully to ensure consistent thickness.
- Place potatoes in a saucepan and cover with heavy cream. Add a good couple pinches of salt. Bring to a gentle boil over medium heat until just barely fork tender.
- While potatoes are cooking, cut the dark green tops from the leeks. Discard or set aside for stock making. Slice leek lengthwise then slice into half moons, about 1/4" thick. Rinse and pat dry.
- Wash and dry kale, then remove leaves from the thick stalks. Roughly chop.
- Heat butter in large saute pan over medium low heat. When butter is melted add leeks and a pinch of salt. Saute gently until softened, stirring occasionally to prevent charring.
- When potatoes are mostly soft, pour into a colander placed over a bowl to catch the cream.
- Spread the potatoes out on platter or sheet pan to cool and return cream to pan. Simmer on low until reduced by half, season with salt and pepper to taste.
- Add chopped kale to the leeks and stir to coat kale with the oil. Cover with lid to steam.
- Once kale as softened, remove lid and saute until tender. Taste and adjust salt as needed.
- When cream has reduced, layer half the potatoes in an 9×13 pan. Top with kale and leek mixture. Pour over half the cream. Layer remaining potatoes and top with the rest of the cream.
- Bake for 20 – 25 minutes, or until top is golden and bubbly. Add chopped parsley if desired and serve.
Nutrition
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Nutrition information and cooking times are provided as a best estimate. Values may vary based upon ingredients and equipment.
I used vegan oat cream instead of dairy and it was absolutely delicious! Such a yummy recipe!
Thanks for sharing how you made it! I’m so glad it worked out for you!
I like the idea of the vegs,
Sounds like a lot of extra steps that are not needed.
Why not just saute the vegs,
Butter the pan, Layer the potatoes, a bit of grated nutmeg, vegs, cream, potatoes vegs nutmeg, cream and then some grated parm or favorite hard cheese.
Bake until bubbly
Happy Thanksgiving
Hi Kate, I’m glad you like the sound of the added veg. I can appreciate wanting to save some time! For this recipe (and really every time I make scalloped potatoes now), I find the extra steps of cooking the potatoes in cream and then reducing the cream ARE needed for the best possible flavor and texture, rather than just efficiency. My recipes are designed with those things in mind first and foremost. I also don’t include nutmeg or cheese in this, though they may be lovely additions! I hope your recipe turns out well, if you ever try mine, I’d love to hear how it goes. Happy Thanksgiving!