Kalyn's Kitchen

Roasted White Sweet Potatoes with Red Onions

Roasted White Sweet Potatoes with Red Onions also have added flavor from rosemary and Parmesan and these are delicious! And savory sweet potatoes are a nice change from the usual sugary sweet potato dishes! 

PIN Roasted White Sweet Potatoes to try them later!

Roasted White Sweet Potatoes with Red Onions finished dish on serving plate

Through the years I’ve added a lot of ideas for roasted vegetables  to my collection for Thanksgiving Recipes, and this favorite recipe for Roasted White Sweet Potatoes with Red Onions is something that’s a great alternative to the overly-sweet orange sweet potatoes you often see this time of year. And if you’ve been paying attention, you know how I love savory sweet potato recipes, even though I never liked the overly sweet ones.

In case you need help with the mental image, think golden roasted white sweet potatoes, crispy caramelized red onions, a hint of rosemary,  and a little Parmesan cheese tossed with the sweet potatoes when they come out of the oven. This is something you might enjoy if you aren’t a fan of the sweeter orange-fleshed sweet potatoes.

What’s the Difference Between Yams and Sweet Potatoes?

I’m also going to include a little sweet potato information here as a PSA for all those families who talk about the “candied yams” they have at Thanksgiving. Many people in the U.S. are confused about the differences between sweet potatoes and yams, (although the white-skinned types used in this dish are almost always called sweet potatoes.) Unless you’ve lived in the tropics, the orange-fleshed “yams” you’ve eaten are really sweet potatoes, but the confusion started when they were purposely labeled yams to distinguish them from the white fleshed type.

True yams are grown in Africa and Asia, and are drier and starchier than sweet potatoes.  And you might like to know that Sweet potatoes are only distantly related to potatoes, which is probably why they’re so much lower on the glycemic index. Check out Sweet Potato Recipes for more ideas for sweet potatoes!

Roasted White Sweet Potatoes process shots collage

How to Make Roasted White Sweet Potatoes with Red Onions:

(Scroll down for complete recipe with nutritional information.)

  1. The first photo shows two of the white sweet potatoes used in this recipe, and in the back is an orange-fleshed sweet potato of the type often called “yams” in U.S. grocery stores.
  2. Peel sweet potatoes and cut up into pieces slightly over one inch. Chop the red onions just slightly smaller. 
  3. Toss sweet potatoes and onions with the oil, 1 tablespoon of the chopped rosemary, salt, and fresh ground black pepper to taste, and spread out on a roasting pan.  (Mine are a little crowded; use two pans if you need to.)
  4. Roast at 400F/200C for 35-40 minutes or longer, turning occasionally.
  5. While the sweet potatoes are roasting, VERY finely chop the second tablespoon of fresh rosemary and mix with freshly-grated Parmesan. (You can omit the rosemary if you don’t have it.)
  6. Toss the hot sweet potatoes and onions with the Parmesan-rosemary mixture and serve hot.

More Delicious Ideas for Savory Sweet Potatoes:

Roasted White Sweet Potatoes in Garlic and Ginger from Weird Combinations
Grilled Sweet Potato Salad from Kalyn’s Kitchen
Butternut Squash and White Sweet Potato Mash from Sweet Basil
Twice-Baked Sweet Potatoes with Feta from Kalyn’s Kitchen
Mirin Sweet Potatoes from Use Real Butter
Favorite Healthy Sweet Potato Recipes ~ Kalyn’s Kitchen

Roasted White Sweet Potatoes with Red Onions finished dish on serving plate

Roasted White Sweet Potatoes with Red Onions

Yield 4 servings
Prep Time 20 minutes
Cook Time 40 minutes
Total Time 1 hour

Roasted White Sweet Potatoes with Red Onions are a delicious change from the usual sugary sweet potato dishes that show up this time of year!


  • 3 medium white-fleshed sweet potatoes (see notes)
  • 2 medium red onions
  • 2 T olive oil
  • 2 T finely chopped fresh rosemary, divided (see notes)
  • 1 tsp. sea salt
  • fresh ground black pepper to taste
  • 1/2 cup freshly grated Parmesan cheese


  1. Preheat oven to 400F/200C and spray a large roasting pan with non-stick spray or mist with olive oil.
  2. Peel potatoes and remove skin from onions. (Sweet potatoes could also probably be left unpeeled, but I did peel them.)
  3. Cut sweet potatoes into pieces just over 1 inch and onions into pieces slightly smaller.
  4. Finely chop fresh rosemary, or grind the rosemary (and use a bit less) if you only have dried rosemary.
  5. Place sweet potatoes and onions in plastic bowl and toss with olive oil, 1 T chopped rosemary, sea salt, and fresh ground black pepper.
  6. Arrange in single layer on roasting pan and roast until vegetables are cooked through and slightly browned, about 35-40 minutes or slightly longer.  (I would stir a few times.)
  7. Combine fresh-grated Parmesan and very finely chopped rosemary in small bowl.
  8. Remove vegetables from oven and toss with Parmesan-rosemary mixture.
  9. Serve hot.


The white sweet potatoes will have a much whiter skin than the orange-fleshed ones. I’ve also made this with frozen rosemary, If you only have dried rosemary I would grind it and use a bit less. Here's how to do frozen rosemary if you have it in the garden.

This recipe slightly adapted from Bon Appetit, November 2002.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 212Total Fat: 11gSaturated Fat: 3gTrans Fat: 0gUnsaturated Fat: 7gCholesterol: 11mgSodium: 840mgCarbohydrates: 25gFiber: 4gSugar: 8gProtein: 6g

Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.

If you make this recipe I'd love to hear how it turns out. Leave a star rating or share on social media with the hashtag #KALYNSKITCHEN, thanks!

Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Sweet potatoes are a good vegetable choice for phase two or three of the original South Beach Diet, and Roasted White Sweet Potatoes with Red Onionswould be a good alternative to sweet potatoes cooked with butter and brown sugar. Sweet potatoes are too high in carbs for a strict low-carb diet plan.

Find More Recipes Like This One:
Use the Diet Type Index to find recipes suitable for a specific eating plan. You can also Follow Kalyn’s Kitchen on Pinterest to see all the good recipes I’m sharing there.

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    36 Comments on “Roasted White Sweet Potatoes with Red Onions”

  1. Hi Kalyn,

    Thanks for the great recipe. I never used to like sweet potatoes but when I went vegetarian my doctor suggested eating more for protein, now I can’t get enough of them. I also noticed the long list of other recipes using sweet potatoes. Thanks for all of them.

  2. We usually use sweet potatoes for dessert. This looks like a must-try.

  3. What a great idea to use red onion, Kalyn! It looks beautiful and I bet it tastes great too. We often oven roast yams but don’t often add onions or herbs. We really should – it looks fantastic.

    I think I’ve only eaten sweet potato once and cannot quite recall the flavour.

    We never peel our yams (or our regular potatoes either). We really like the flavour and texture offered by the skin.


  4. You are quickly filling up my favourites 🙂 I’m going to soon have to create a folder especially for you 🙂

  5. Patricia, yes I think you could use regular potatoes here. I’d definitely leave the skin on with regular potatoes too. I think it would be great with Yukon gold potatoes, but you could use any type I’m sure.

  6. Kalyn, do you think I could make this dish using regular potatoes?? Joao would love it!

  7. Once again, in a fortuitous coincidence, I have red onions and sweet potatoes at home – hurray! This looks fab. I adore sweet potatoes – had them mashed with some pork & chili sausages this week – realyl delicious.

  8. Yams are sweet potatoes? I didn’t know that at all. Thanks!

  9. Thanks for the good information about sweet potatoes and yams — and for this delicious recipe.

  10. Never tried roasted sweet potatoes before, but sounds delicious.

  11. This is a great dish to have with so many meals….love it!

  12. It’s funny, I don’t mind sweet potatoes, but we hardly ever eat them, not sure why. One thing I’ve found is they’re really great in soups, this recipe should get a run though, its got all the flavours I like.

  13. This is a recipe ‘as good as it gets’, Kalyn!

  14. I am a big fan of sweet potatoes! This sounds really great, kalyn! I may add some feta into it instead of parmesan though. (feta and sweet potatoes are my fav combo).

  15. I love roasted sweet potatoes. I usually keep it really simple, this looks like a great way to jazz it up a bit.

  16. I love sweet potatoes! For me they are a very traditional holiday food – not the candied kind, but roasted or baked. The addition of the red onions is wonderful… and the rosemary~

  17. Peter, that’s just what I thought when I saw the recipe.

    Maria, me too. I have to narrow it down, plus I’m going to my sisters where there are little kids who won’t eat anything interesting.

    Tanna, I’d love to come to your house!

  18. Well, WOW! I’m thinking we’re going to invite some extra people if I cook everything I’ve got on the list.

  19. Ok, now I have to make this for Thanksgiving too! My list is long…but oh so good! Thanks for all your recipe ideas!

  20. Wonderful, noted, tagged! Why not, all these ingredients work with regular potato, should be fine here too.