Creamy Potato Gratin with French Onion Soup Mix

Serve warm, scattered with fresh herbs, alongside a simple salad or roast. It’s rich, comforting and quietly impressive — the kind of dish that makes guests think you’ve gone to far more effort than you have.

🌿 Make-Ahead & Storage Notes

This is a perfect prep-ahead dish — ideal for calm, stress-free hosting.

Make ahead (unbaked):
Assemble the gratin, cover tightly and store in the fridge for up to 24 hours.
When ready to cook, bring it out for 20–30 minutes before baking, then cook as usual.
Make ahead (baked):
Bake fully, cool, then refrigerate. Reheat covered at 160°C until warmed through, then uncover briefly to crisp the top.
Leftovers:
Keeps beautifully for 2–3 days in the fridge and reheats well — making it perfect for next-day lunches.

💡 Hosting tip: This is one of those dishes that actually gets better as the flavours settle.

🔪 Why the Vegetable Chopper Changes Everything

Even slices are the difference between a good gratin and a perfect one. I 100% LOVE my Amazon Vegie Slicer so I am unashamedly going to share it with you here. You'll use it over and over, from Sunday nbight lunch prep to whipping up platters with ease, you will store this under you sink in the box and it will become the one item you become quite smug about. Because hey... when someone sees your platter FULL of seasonal vegetables perfectly chopped, or a lunch stacked with perfection, or this potato dish perfectly presented they will think you slaved like a domestic god.....

Here is a link to the one I love with no breaking the bank: https://amzn.to/3NS1Vsn

Using a vegetable chopper:

Ensures consistent, thin slices that cook evenly
Saves significant prep time (especially for larger dishes)
Creates those beautiful, layered results that look as good as they taste

It’s the quiet shortcut that makes this dish feel polished without the effort.

🥓 Ways to Elevate the Dish

This base recipe is beautiful on its own, but it also invites a few simple upgrades:

Add Bacon

Layer in cooked, chopped bacon between the potatoes for a deeper, savoury flavour.

Add Leek

Swap or combine onion with thinly sliced leek for a softer, slightly sweet finish that feels a little more refined.

💡 Best of both: Bacon + leek together creates a rich, restaurant-style variation.

🍠 A Simple Twist: Add Sweet Potato

For something a little unexpected:

Replace half the potatoes with sweet potato
Alternate layers for a beautiful colour contrast

This adds:

A subtle natural sweetness
A more complex flavour profile
A visually striking finish on the table

It’s a small change that makes the dish feel considered and elevated.

🌿 Homegrown & Hosted Note

This is the kind of recipe that does the work for you. Prepared ahead, layered with ease, and adaptable to whatever you have on hand — it brings a sense of calm to the kitchen and confidence to the table.

Exactly how hosting should feel.

Note: this Blog post contains Amazon Affiliate links and I may receive a commission if you purchase this product which helps me create more free content.