Cajun Sweet Potato Gratin

Featured in: Sweet Comforts

This Cajun-inspired dish features layers of tender sweet potatoes baked with sautéed onions, rich cream, and a blend of robust Cajun spices. Gruyère and Parmesan cheeses add a luscious texture and depth of flavor, while a kick of cayenne and smoked paprika brings warmth. Easy to prepare ahead, it makes a vibrant, golden centerpiece for any table, serving as a bold vegetarian main or a flavorful side alongside roasted meats or fish. Garnish with parsley for a fresh finish and enjoy this creamy, spicy gratin that perfectly blends comfort and southern flair.

Updated on Thu, 23 Oct 2025 14:25:03 GMT
Golden-brown Cajun Sweet Potato Gratin bubbling hot from the oven, a creamy, spicy delight. Pin
Golden-brown Cajun Sweet Potato Gratin bubbling hot from the oven, a creamy, spicy delight. | panpatriot.com

Cajun Sweet Potato Gratin brings bold southern spice and cozy comfort to the table with layers of tender sweet potatoes, a luscious creamy sauce, and the irresistible kick of Cajun seasoning. Whether you are after a crowd pleasing side or a vegetarian main, this dish transforms simple ingredients into a beautiful bake that shines at any gathering.

I discovered this recipe when trying to make sweet potatoes more exciting for my family holidays. Its deep flavor and gorgeous color quickly moved it to centerpiece status at our gatherings.

Ingredients

  • Sweet potatoes: Bring a natural sweetness and beautiful orange color. Select firm potatoes free of blemishes
  • Yellow onion: Adds gentle savory undertones. Choose one that feels heavy for its size
  • Garlic: Brings vital pungency and depth. Fresh cloves give the best aroma
  • Heavy cream: Brings a rich silky sauce. Use the highest fat cream you can find
  • Whole milk: Adds just the right amount of lightness
  • Gruyère cheese: Gives a nutty melt and gorgeous stretch. Look for a block and grate it yourself
  • Parmesan cheese: Adds salty depth and layers of umami. Freshly grated always outshines anything pre packed
  • Unsalted butter: Lets you control the seasoning. Choose sweet cream for best flavor
  • Cajun seasoning: Delivers zesty spice and complexity. Seek out a blend with paprika and dried herbs
  • Smoked paprika: Adds subtle smokiness. Spanish smoked paprika has a beautiful aroma
  • Black pepper: Lends gentle heat and backbone. Use freshly cracked for true flavor
  • Salt: Enhances every ingredient. Go for fine sea salt for even seasoning
  • Cayenne pepper: Supplies extra boldness if you love heat
  • Fresh parsley: Provides a balancing fresh brightness. Look for leaves with no droop or yellowing

Instructions

Preheat the Oven:
Set your oven to 200C or 400F so it reaches temperature while you prep everything else. Grease a 9 by 13 inch baking dish with butter making sure you coat every corner for easy serving later
Sauté the Aromatics:
Melt the butter in a small saucepan over medium heat. When it foams add sliced onion and minced garlic. Sauté gently for about three to four minutes. Stir often until everything softens and the onions smell sweet. Remove from the heat to avoid browning
Mix the Creamy Sauce:
In a bowl whisk together heavy cream whole milk Cajun seasoning smoked paprika black pepper salt and cayenne pepper if you want a spicier kick. Whisk until everything blends into a pinkish silky liquid
Layer the Potatoes:
Layer half your sweet potato slices into the baking dish overlapping slightly for even coverage. Slight overlap ensures even cooking
Add the Savory Layers:
Spread half the sautéed onions and garlic over the sweet potatoes. Sprinkle evenly with half the Gruyère and Parmesan cheeses. This builds flavor in every bite
Repeat and Finish the Layers:
Repeat with the rest of your sweet potatoes onions and cheeses. Stack the layers so you reach the top of the dish
Pour and Press:
Pour the cream mixture evenly over the entire dish. Gently press down on the layers with your hands or a spatula so the cream seeps through every nook
Bake Covered:
Cover the dish tightly with foil. Bake for thirty minutes so the sweet potatoes begin to soften and all flavors mingle
Uncover and Brown:
Remove the foil. Return the dish to the oven for another fifteen minutes. The top should bubble and turn beautifully golden and potatoes should be fork tender
Rest and Garnish:
Let the gratin rest ten minutes out of the oven before serving. This helps set the layers and makes slicing easier. Garnish with chopped parsley for a flash of color and flavor
Close-up of warm, layered Cajun Sweet Potato Gratin, cheese melted, garnished with fresh parsley. Pin
Close-up of warm, layered Cajun Sweet Potato Gratin, cheese melted, garnished with fresh parsley. | panpatriot.com

My favorite part is the way Gruyère brings an almost smoky melt to the dish. My relatives now ask for this gratin every Thanksgiving and it always wins over guests who thought they did not like sweet potatoes

Storage Tips

Once baked let the gratin cool to room temperature. Cover tightly and refrigerate for up to three days. The flavors get deeper with time. For best results reheat at 180C or 350F covered until hot

Ingredient Substitutions

If Gruyère is not available sharp cheddar or Emmental bring a new personality. Use coconut cream and non dairy cheese for a rich vegan version. Swap in red onions for a sweeter twist

Serving Suggestions

This gratin shines with roasted turkey glazed ham or grilled fish. For a vegetarian meal pair with a lemony salad or sautéed greens. Leftover wedges make a cozy next day lunch

Cultural and Seasonal Notes

Sweet potato gratins draw from French and southern United States traditions. Cajun spices reflect Louisiana's multicultural roots making this dish bold and welcoming. It is a lovely way to enjoy root vegetables at their peak

Savory bake: Homemade Cajun Sweet Potato Gratin, a flavorful alternative to traditional sweet potatoes. Pin
Savory bake: Homemade Cajun Sweet Potato Gratin, a flavorful alternative to traditional sweet potatoes. | panpatriot.com

This dish delivers vibrant color and bold flavor to any spread. Serve piping hot and enjoy the comforting layers with every bite

Recipe Questions

What makes this dish Cajun?

The use of Cajun seasoning, smoked paprika, and optional cayenne gives the gratin its signature spicy-sweet southern flavor.

Can I make this dairy-free?

Substitute coconut cream and plant-based milk, plus vegan cheeses, for a delicious dairy-free version.

What’s the best way to slice sweet potatoes?

For even, thin slices, use a mandoline slicer or a sharp chef’s knife. Uniform slices ensure balanced cooking.

How can I add extra heat?

Add more cayenne pepper to the spice mix or use a hotter Cajun blend for a more pronounced kick.

What can I serve with this gratin?

It pairs well with roasted meats, grilled fish, or a crisp green salad as a satisfying vegetarian main.

Can it be made ahead?

You can assemble and refrigerate the dish up to one day in advance; reheat gently before serving for best texture.

Cajun Sweet Potato Gratin

Spicy Cajun flavors meet creamy sweet potatoes for a standout vegetarian side—golden, comforting, and satisfying.

Prep duration
20 min
Cooking duration
45 min
Total duration
65 min

Category Sweet Comforts

Difficulty Medium

Origin Cajun, Southern American

Yield 6 Servings

Dietary requirements Vegetarian, Gluten-free

Ingredients

Vegetables

01 2.5 lbs sweet potatoes, peeled and thinly sliced
02 1 medium yellow onion, thinly sliced
03 2 cloves garlic, minced

Dairy

01 1 cup heavy cream
02 1/2 cup whole milk
03 1 cup grated Gruyère cheese
04 1/2 cup grated Parmesan cheese
05 2 tablespoons unsalted butter

Spices & Seasonings

01 2 teaspoons Cajun seasoning
02 1/2 teaspoon smoked paprika
03 1/2 teaspoon freshly ground black pepper
04 1 teaspoon salt
05 1/4 teaspoon cayenne pepper (optional, for extra heat)

Garnish

01 2 tablespoons chopped fresh parsley (optional)

Directions

Step 01

Prepare Oven and Dish: Preheat oven to 400°F. Grease a 9x13 inch baking dish with butter.

Step 02

Sauté Aromatics: In a small saucepan over medium heat, melt the butter. Add sliced onion and minced garlic; sauté for 3 to 4 minutes until softened and fragrant. Remove from heat.

Step 03

Mix Seasoned Cream: In a mixing bowl, whisk together heavy cream, whole milk, Cajun seasoning, smoked paprika, black pepper, salt, and cayenne pepper if using.

Step 04

Layer Ingredients: Arrange half of the sweet potato slices in the prepared baking dish, overlapping slightly.

Step 05

Add First Layer Toppings: Spread half of the sautéed onions and garlic over the sweet potatoes. Sprinkle with half of the Gruyère and Parmesan cheeses.

Step 06

Repeat Layering: Top with remaining sweet potatoes, onions, and cheeses.

Step 07

Add Cream Mixture: Pour the seasoned cream mixture evenly over the layered ingredients. Press down gently so the cream penetrates all layers.

Step 08

Initial Bake: Cover the dish tightly with foil and bake for 30 minutes.

Step 09

Brown and Finish: Remove foil and bake for an additional 15 minutes, or until the top is golden brown and sweet potatoes are tender.

Step 10

Rest and Garnish: Let stand for 10 minutes after baking. Garnish with fresh parsley if desired before serving.

Necessary tools

  • Chef’s knife
  • Mandoline slicer (optional)
  • Mixing bowls
  • Saucepan
  • 9x13 inch baking dish
  • Foil

Allergy information

Review each ingredient for potential allergens and consult with healthcare providers if you're uncertain.
  • Contains milk and cheese (dairy).
  • Cajun spice blends may include gluten or other allergens. Check product labels if sensitive.

Nutrition facts (per portion)

These values are estimates only and shouldn't replace professional medical guidance.
  • Calories: 325
  • Fat: 18 g
  • Carbohydrates: 35 g
  • Protein: 7 g