Creamy Sweet Potato Gratin

by Becca
6 people
1 hr 55 min

This creamy sweet potato gratin is ultra luxurious, with buttered leeks and a hint of smoked paprika. Perfect for a special occasion!

Have you ever cooked something that barely even makes it to the dinner table, because you just can’t stop nibbling it straight from the dish? That was me with this creamy sweet potato gratin. It. Is. Incredible.

Sweet potato gratin

I’ll admit, sweet potato isn’t usually my favourite vegetable. I’ll take a regular French fry over a sweet potato one any day of the week.

But this sweet potato gratin… wow. It’s definitely converted me to the wonders of sweet potato.

Thin slices of sweet potato are baked in a creamy, cheesy sauce – with garlicky buttered leeks, just because. The potato absorbs the sauce and becomes soft and creamy, and I also added my favourite spice of all time, smoked paprika, which brings some depth. The flavour is just incredible.

The finished dish doesn’t feel overly sweet, as the flavour of the sweet potato is perfectly balanced by the salty cheese, as well as the smokiness of the paprika.

Can you use regular potatoes instead?

If you’re not a sweet potato fan, you can swap them out for regular potatoes. I’d actually recommend giving the sweet potatoes a try, as the hint of sweetness is absolutely incredible in the finished dish, even if it’s not usually your thing.

But if regular potatoes are all you have on hand, you can use them instead.

Creamy Sweet Potato Gratin
Recipe details
  • 6  people
  • Prep time: 30 Minutes Cook time: 85 Minutes Total time: 1 hr 55 min
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  • 1 tbsp butter
  • 1 large leek, quartered lengthwise then sliced
  • 3 cloves garlic, minced
  • 600 g (~ 1 1/3 lb) sweet potato (1 large or 2 small)
  • 500 ml (~ 2 cups) single cream
  • 1 tsp smoked paprika
  • 1 tsp salt
  • 1 tsp black pepper
  • 1 tsp dried thyme
  • 100 g (~ 3 1/2 oz) vegetarian parmesan-style cheese, finely grated

Melt the butter in a frying pan, and add the sliced leek and minced garlic. Cook over a medium-low heat for 5-10 minutes, until the leek is very soft but not overly browned.
Peel the sweet potato, and cut it into thin slices (ideally 2-3mm).
Transfer the cream into a jug, and add the smoked paprika, salt and pepper, and dried thyme. Mix thoroughly to combine.
Pour about a tablespoon of the cream mixture into the bottom of a baking dish (mine measured approximately 8 x 8 inches), and spread it around. This helps to stop the potato sticking to the bottom of the dish.
Now begin layering your ingredients. Add a single layer of sweet potato slices, scatter a few buttered leeks on top, and a light sprinkling of finely grated parmesan. Drizzle over a little more of the cream mixture. Repeat these layers until you’ve used all of the ingredients. Finish the dish by pouring any remaining cream on top, and scattering over any remaining cheese.
Add a lid to the dish, or cover tightly with some kitchen foil. Bake at 190°C (Gas Mark 5 / 375°F) until the sweet potato is soft, and offers no resistance when you insert a sharp knife. My bake took about 1 hour 25 minutes, but the exact time will depend on exactly how thinly you sliced your potatoes.
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  • Sdc17433512 Sdc17433512 on Dec 12, 2021

    Have you ever tried this recipe using frozen sweet potatoes

  • Helena Brus Helena Brus on Dec 23, 2021

    Oh yum. What is single cream (can't find it in a U.S. grocery store)?

    • See 1 previous
    • Becca Becca on Jan 06, 2022

      In the UK we have double cream and single cream - double cream just has a higher fat content than single cream. Single cream is around 18-19% fat, so use whatever's roughly equivalent to that.