THIS Creamy Garlic Parmesan Yam Gratin recipe COMES IN Tender layers of thinly sliced yams baked in a creamy garlic-Parmesan sauce, topped with golden Gruyère and crispy Parmesan breadcrumbs. This rich and savory yam gratin is the perfect side dish for Thanksgiving, Christmas, Sunday dinner, or any cozy fall meal.

You may also like my Maple Bacon Sweet Potatoe Gratin dish

If you’re looking for a side dish that feels a little special but is surprisingly simple to make, this Creamy Garlic Parmesan Yam Gratin belongs on your table.

Thin slices of tender yams are layered in a rich garlic and herb cream sauce, then baked until bubbling and tender. The top becomes beautifully golden and crisp, while the inside stays creamy and silky.

Unlike a traditional sweet potato casserole, this recipe is completely savory. There is no brown sugar, maple syrup or marshmallow topping. Instead, the natural sweetness of the yams is balanced with garlic, Parmesan, Gruyère, fresh thyme and black pepper.

It’s cozy, comforting and absolutely delicious.

🧡 Why You’ll Love This Yam Gratin

• Creamy and incredibly comforting
• Completely savory, rather than sweet
• Made with simple ingredients
• Beautiful golden, cheesy topping
• Perfect for fall and winter entertaining
• Wonderful Thanksgiving and Christmas side dish
• Can be assembled ahead of time
• Pairs beautifully with turkey, ham, roast beef and chicken
• Makes an impressive side dish without complicated preparation

🥔 What Are Yams?

In many Canadian grocery stores, orange-fleshed sweet potatoes are commonly labeled as yams, even though true yams are a different type of root vegetable.

For this recipe, use orange-fleshed sweet potatoes or the orange-fleshed “yams” commonly sold in Canadian grocery stores. They have the beautiful colour, creamy texture and natural sweetness that make this gratin so good.

How to Make Creamy Garlic Parmesan Yam Gratin

1. Prepare the Yams

• Preheat the oven to 375°F.
• Butter a large oval baking dish.
• Peel the yams and slice them into approximately ⅛-inch thin slices.
• Try to keep the slices as uniform as possible so they cook evenly.

Tip: A mandoline slicer makes this step much easier, but a sharp knife works perfectly well.

2. Make the Garlic Cream Sauce

• Add the butter to a medium saucepan over medium-low heat.
• Add the minced garlic.
• Cook for approximately 30–60 seconds, just until fragrant. Do not let the garlic brown.
• Add the heavy cream and milk.
• Stir in the thyme, salt, pepper and nutmeg.
• Warm gently for 3–4 minutes.

The mixture should be hot and fragrant but does not need to boil.

• Remove from the heat.
• Stir in ½ cup of the Parmesan cheese.

3. Layer the Yams

• Arrange a layer of sliced yams across the bottom of the prepared baking dish.
• Spoon some of the garlic cream sauce over the yams.
• Sprinkle with some of the Gruyère.
• Repeat the layers until all the yams have been used.
• Pour the remaining cream sauce over the top.
• Finish with the remaining Gruyère and Parmesan.

Try to distribute the cheese evenly so the entire surface becomes golden and bubbly.

4. Bake

• Cover the baking dish tightly with aluminum foil.
• Bake for 40 minutes.
• Remove the foil.
• Continue baking for another 20–25 minutes, or until the yams are completely tender and the top is golden and bubbling.

If the top needs additional colour, place it under the broiler for 1–2 minutes at the end.

Watch it carefully—the cheese can brown very quickly.

5. Make the Crispy Parmesan Topping

While the gratin is baking:

• Combine the panko breadcrumbs, Parmesan, melted butter, thyme, salt and pepper in a small bowl.
• Mix until the breadcrumbs are evenly coated.

During the final 8–10 minutes of baking, sprinkle the breadcrumb mixture evenly over the gratin.

Continue baking uncovered until the topping is golden and crisp.

6. Rest Before Serving

• Remove the gratin from the oven.
• Allow it to rest for 10–15 minutes before serving.
• Garnish with fresh thyme and parsley.
• Add a little extra Parmesan if desired.

The resting time allows the creamy sauce to thicken slightly and makes the gratin much easier to serve.

🍽️ What to Serve With Yam Gratin

This is an incredibly versatile side dish.

Serve it alongside:

• Roast turkey
• Christmas ham
• Roast beef
• Herb-roasted chicken
• Pork tenderloin
• Roast chicken
• Prime rib
• Green beans
• Brussels sprouts
• Roasted carrots
• Cranberry sauce

For a holiday table, pair it with turkey, cranberry sauce and a crisp green vegetable for a beautiful combination of flavours and colours.

🍂 Perfect for Thanksgiving

This yam gratin makes a wonderful alternative to the traditional sweet potato casserole.

Instead of a very sweet side dish, you get something savory, creamy and cheesy that works beautifully alongside turkey and gravy.

And because it can be assembled ahead of time, it’s especially useful when you’re trying to get a Thanksgiving dinner onto the table without making every dish at the last minute.

🎄 Perfect for Christmas Dinner

The golden, bubbling top makes this gratin beautiful enough for a holiday table.

It pairs particularly well with:

Ham + Yam Gratin + Brussels Sprouts + Cranberry Sauce

or

Roast Beef + Yam Gratin + Green Beans + Yorkshire Pudding

🧀 Cheese Options

Gruyère gives this gratin a rich, slightly nutty flavour, but you have options.

You can substitute:

• Sharp white cheddar
• Aged cheddar
• Fontina
• Swiss cheese
• Emmental
• A combination of Gruyère and Parmesan

For the best flavour, I recommend freshly grating the cheese rather than using pre-shredded cheese.

🌿 Can I Change the Herbs?

Absolutely.

Fresh thyme is my favourite for this recipe, but you can also add:

• Rosemary
• Sage
• Parsley
• A small amount of fresh chives

For a holiday version, a combination of thyme and sage is especially delicious.

🥘 Make-Ahead Instructions

This recipe is excellent for entertaining.

You can assemble the gratin up to 24 hours ahead of time.

• Assemble the entire gratin in the baking dish.
• Cover tightly with foil.
• Refrigerate until ready to bake.
• Remove from the refrigerator approximately 30 minutes before baking.
• Bake according to the recipe directions.

For the crispiest topping, prepare the Parmesan breadcrumb mixture separately and add it during the final 8–10 minutes of baking.

Because the gratin is going into the oven cold, you may need to add approximately 10–15 minutes to the covered baking time.

❄️ Storage

Store leftover gratin covered in the refrigerator for up to 4 days.

Reheat individual portions in the microwave or reheat the entire dish covered with foil in a 350°F oven until warmed through.

For the best texture, add a small splash of cream or milk before reheating if the gratin seems dry.

🧊 Can You Freeze Yam Gratin?

Yes, although the texture of the cream sauce can change slightly after freezing.

For the best results:

• Cool the gratin completely.
• Wrap tightly.
• Freeze for up to 2 months.
• Thaw overnight in the refrigerator.
• Reheat covered at 350°F until hot.
• Remove the foil during the final few minutes to crisp the top.

For the best holiday texture, I recommend making it fresh or assembling it one day ahead rather than freezing.

💡 Recipe Tips

Slice the yams evenly.

The thinner and more uniform your slices, the more evenly the gratin will cook.

Don’t boil the cream.

A gentle warming is all you need. Boiling the cream can cause the sauce to become less smooth.

Use freshly grated cheese.

Freshly grated Parmesan and Gruyère melt more smoothly and give you better flavour.

Let it rest.

Don’t rush straight from the oven to the table. A 10–15 minute rest allows the sauce to settle.

Watch the broiler.

That final bit of broiling can create a beautiful golden crust, but it can also burn quickly.

Frequently Asked Questions

Are yams and sweet potatoes the same thing?

Not technically. True yams are a different root vegetable. However, orange-fleshed sweet potatoes are commonly labeled as yams in Canadian and North American grocery stores. For this recipe, use the orange-fleshed variety sold as yams or sweet potatoes.

Can I use regular sweet potatoes?

Yes. Orange-fleshed sweet potatoes work perfectly in this recipe.

Can I make this without Gruyère?

Absolutely. Sharp cheddar, Fontina, Swiss or Emmental are all delicious alternatives.

Can I make this recipe without breadcrumbs?

Yes. Simply omit the panko topping and allow the cheese to brown naturally on top.

Can I use milk instead of heavy cream?

You can, but the gratin will be noticeably lighter and less creamy. For the richest result, heavy cream is recommended.

How do I know when the yams are done?

Insert a thin knife into the centre of the gratin. It should slide easily through the layers without resistance.

Why is my gratin watery?

Yams can release moisture while cooking. Make sure the cream sauce isn’t overly thin, don’t add extra liquid, and allow the finished gratin to rest for 10–15 minutes before serving.

🍠 The Difference Between This and a Sweet Potato Casserole

If you’re used to sweet potato casseroles topped with brown sugar, marshmallows or pecans, this recipe is a completely different experience.

This gratin is savory and creamy, with garlic, Parmesan, Gruyère and herbs creating the flavour.

The yams provide just enough natural sweetness to balance all that richness.

Think of it as:

Classic potato gratin meets creamy garlic Parmesan potatoes—with beautiful orange yams.

⭐ My Best Tip

Don’t be shy with the fresh Parmesan and black pepper.

The yams have a natural sweetness, so the salty Parmesan, earthy thyme, garlic and pepper are what bring the whole dish into balance.

And that crispy Parmesan breadcrumb topping?

That’s the part everyone will be fighting over.

🍽️ Recipe at a Glance

Recipe: Creamy Garlic Parmesan Yam Gratin
Prep Time: 20 minutes
Cook Time: 1 hour 5 minutes
Resting Time: 10–15 minutes
Total Time: Approximately 1 hour 40 minutes
Servings: 8
Category: Side Dish
Cuisine: American / Canadian-inspired
Perfect For: Thanksgiving, Christmas, Fall & Winter

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🍁 A Cozy Side Dish for the Season

There’s something about pulling a bubbling gratin from the oven that makes a meal feel instantly special.

This Creamy Garlic Parmesan Yam Gratin is rich without being overly sweet, comforting without being complicated, and elegant enough for the holiday table.

Whether you’re serving it at Thanksgiving, Christmas or simply making Sunday dinner a little more special, it’s a side dish that’s meant to be shared.

From my kitchen to yours, enjoy!

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