This gluten free sweet potato casserole is creamy and delicious, with a flavorful pistachio oat topping. Simple to make, it's a must-have savory and dairy free side dish for your Thanksgiving dinner!
Special occasions always seem a little bit more about sides than mains, or is that just me? If you're planning your Thanksgiving or holiday recipes, then perhaps you may also like to see my cranberry sauce, cheesy cauliflower mash and creamy potato cauliflower mash. All so tasty!
This sweet potato casserole feels very decadent, with hints of spice, nuts and herbs. We keep it more on the savory side, focusing on the fragrant spices rather than more traditional ingredients of marshmallows and brown sugar. It's a little less sweeter but equally delicious!
⭐ Why this recipe is so good
- Savory flavors. We leave out most of the sweet stuff and enjoy fragrant spices, nuts and herbs for flavour.
- Dairy and gluten free. As we use non-dairy milk and gluten free oats, this sweet potato casserole is suitable for both dietary requirements. It's also refined sugar free!
- Low histamine - for my low histamine readers, this uses suitable ingredients in line with the SIGHI list.
All the ingredients and their quantities are set out in the recipe card below.
Some notes on a few of them:
- Sweet potatoes - choose fresh unbruised produce, and give them a good scrub before use!
- Oats - a great swap for flour or other wheat-based toppings. Use a brand such as Bob's Red Mill gluten-free oats if you are coeliac or sensitive to gluten.
- Sage, rosemary and ginger powder - these are the main flavors of the casserole and enhance the mashed sweet potatoes so well.
- Pistachios - used instead of pecans, be sure to use unsalted nuts that have not already been roasted or flavored in any way.
📖 Swaps and variations
Swap pistachios for pecans. I use pistachios in this recipe as it is more suitable for my low histamine readers, but pecans work so well and are the more traditional nut for this casserole.
Adjust the amount of spice. The quantity used gives a nice hum of heat, and a fragrant flavor from the sage and rosemary. If you like it more punchy, add a pinch more!
💭 Does sweet potato casserole contain gluten?
Many recipes for sweet potato casserole will not be gluten free as they use flour or non-certified gluten free oats. As we don't use flour in this recipe and use certified gluten free oats instead, it does not contain gluten.
🔪 Step by step instructions
Making this gluten free sweet casserole is so easy to do and perfect for the Thanksgiving table! All the steps are in the recipe card below, but these photos should help guide you:
Peel and dice your sweet potato into small bite-size pieces (image 1).
Bring a pot of water to the boil, then tip in the sweet potato. Bring back to a boil, then reduce the heat to a light simmer (image 2). Cook for 15 minutes or until fork tender.
Recipe tip: as an alternative cooking method, the sweet potato can be steamed.
Tip the sweet potatoes into your food processor, along with the non-dairy milk, sage, ginger powder, olive oil, salt and black pepper (image 3). Blend to make your creamy sweet potato filling.
Blend the oats, pistachios, maple syrup, herbs, garlic powder and olive oil in the food processor (image 4). The mixture will slightly sticky due to the oil and syrup.
Recipe tip: if the topping seems overly dry, add a touch more olive oil. You don't want a 'wet' topping, but one that is slightly sticky.
Spoon the sweet potato mixture into your casserole dish, and use the back of the spoon to smooth it into an even layer (image 5).
Sprinkle the oat pistachio topping over the sweet potato, and add a few more pistachio nuts if you like (image 6). Bake in the oven for 10-12 minutes until the topping has very light browning.
Scatter over some fresh sage leaves if you like, then serve immediately with your Thanksgiving dinner feast!
💭 Recipe tips and notes
- Be sure to use certified gluten free oats to make this sweet potato casserole if you have that dietary requirement.
- Make sure the sweet potatoes are fork tender when boiling (or steaming) them, as we only bake for a short period of time. And nobody likes under-cooked potatoes!
- Prefer a more chunky sweet potato mixture? Simply blend for a little less time in the food processor.
- Adjust the amount of herbs, spices and garlic to taste.
- Definitely keep an eye on the casserole in the last few minutes once in the oven, as the topping can turn fast and we don't want burnt oats!
📋 Frequently asked questions
This casserole is more on the savory side, with the flavor coming from nuts, herbs and spices. It has a touch of maple syrup but isn't the sweet version often made with brown sugar and marshmallows.
You can roast the sweet potatoes, but it will take longer than boiling or steaming. I tend to find that oven space is at a premium for holiday recipes, so I've kept this recipe to as little oven time as possible!
Sweet potato casserole typically uses pecans, so you can use those. My low histamine readers will want to keep to a nut that they know they tolerate well. It is unclear whether pecans are suitable or not as they are not rated on the SIGHI list.
Some tasty sides include my cheesy cauliflower mash, creamy celeriac sweet potato mash and my hasselback butternut squash with maple brown butter.
🍽 More delicious holiday recipes
Mains and sides to enjoy with friends and family for your special occasions. Find lots of ideas on my holiday recipes page, including my popular honey roasted vegetables and ginger Brussels sprouts. Some recent recipes:
Gluten Free Sweet Potato Casserole (Dairy Free)
- Large pot
- Casserole dish
- Food processor
For the topping
- sage leaves
- Preheat the oven to 180C / 360F.
- Peel and dice the sweet potatoes into small pieces.
- Tip the sweet potato into a large pot of water. Bring to a boil, then reduce the heat to a light simmer. Cook for 15 minutes, or until fork tender.
- Transfer the sweet potatoes to a food processor along with the non-dairy milk, olive oil, ginger powder, sage and salt and black pepper (if using). Blend for ten seconds or so, until creamy.
- Make the oat topping by adding the oats, pistachios, maple syrup, olive oil, herbs and garlic powder to a food processor and pulse blending to a fine powder (it will be slightly sticky due to the oil and maple syrup).
- Spoon the sweet potato into a baking dish, and sprinkle on the oat topping. Add a further few pistachio nuts on top. Bake for 10-12 minutes, in the middle or lower half of the oven. Keep an eye on it for any signs of burning in the last few minutes of cook time!
- Sprinkle with some fresh sage leaves, then serve immediately and enjoy!
- Use certified gluten free oats if you have that dietary requirement.
- Ensure the sweet potatoes are fork tender when you boil (or steam) them, as we only bake in the oven for a short time afterwards.
- You can roast the sweet potato, but this will increase the cook time of the recipe.
- If the topping seems too dry after blending, add a touch more olive oil. You want a very slightly sticky texture.
- Watch the casserole towards the end of cook time as it can turn quickly, and the topping can catch and burn.
- This recipe makes quite a bit of topping, so reduce quantities if you only like a little sprinkle.
- Nutritional information is auto-generated and should be understood to be an estimate.
- non-dairy milk has variable scores.
- pepper, scores 2. It is optional.
- ginger scores 1.