I recommend trying Okinawan sweet potatoes, also known as Hawaiian sweet potatoes. They are so delicious, nutritious, and easy to prepare. My favorite way is to pressure cook them in an Instant Pot however you can also cook them in a pot on your stovetop as well. Stovetop instructions are in the notes of the recipe.
This recipe is a “cook once, eat twice” recipe. Use the Instant Pot to pressure cook all of the sweet potatoes, them serve half of them pressure cooked, plain and simple right out of the pot for your first meal and then make a sweet potato mash for your second meal. Of course, if you like them plain or you like them mashed, serve all of the Okinawan sweet potatoes in the way you prefer.
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Update 2/3/2023 – This post was updated with minor edits for clarity.Jump to Recipe
What are Okinawan Sweet Potatoes?
These sweet potatoes have high levels of anthocyanins which is an antioxidant that gives the food a blue appearance. According to SFGate they’re high in vitamin A, potassium, and fiber. I became interested in making Okinawan sweet potatoes because they’re a staple food in Okinawa, an area in Japan known for their longevity. Who doesn’t want to eat more superfoods that taste and smell delicious?
Hawaiian sweet potatoes are a root vegetable in the sweet potato family, they’re beige on the outside and light purple on the inside. Cooked Hawaiian sweet potatoes become a beautiful bright purple and have a light floral fragrance that I love.
You can serve them whole, just peel and eat. Or cut them in half and scoop out the flesh with a spoon or a fork. Or you can let them cool down a bit, peel, and mash with coconut milk or milk of your choice. If I use coconut milk, I as little as possible but feel free to add more coconut milk or milk of your choice until a desired texture.
How to shop and store them?
Look for tan colored sweet potatoes and check that the inside is purplish by looking at the ends or broken off pieces. I pick Okinawan sweet potatoes that are firm and heavy for their size. Skip the potatoes with soft tips or obvious discoloration.
Then I select pieces that are somewhat uniform in shape and size so that they will finish cooking at approximately the same time. A long skinny sweet potato will require less time to cook than a short and thick one.
Small sweet potatoes are about the size of a lemon. I usually pick medium sized ones which are about 6-8 ounces each. A large sweet potato could weigh over 1 pound. Adjust your cooking time depending on the size of your sweet potatoes.
Okinawan sweet potatoes don’t store as well as other kinds of sweet potatoes and since they’re also pricier, I prioritize cooking them as soon as possible. I refrigerate them and cook them within a few days. If you have a dark, cool spot in your home you can store them for about a week.
What’s the best way to cook and serve Hawaiian sweet potatoes?
As with other kinds of sweet potatoes, you can bake, boil, steam, or fry them. I like boiling or pressure cooking them because that’s easy, healthy, and energy efficient. Boiling Okinawan sweet potatoes on the stovetop leaves a black sticky residue on the sides of my pot which I find difficult to scrub off. However, my Instant Pot will pressure cook the sweet potatoes to perfection in less time. I love that my kitchen doesn’t heat up, and the pot is easy to clean and ready to use for another Instant Pot recipe.
My favorite way to eat Hawaiian sweet potato is to peel them when they’re cool enough to touch and add just enough coconut milk to mash them into a chunky mashed potato side dish that goes well with Instant Pot Kalua Pork with Cabbage (or you can make Slow Cooker Kalua Pork with Bacon and Cabbage Recipe). This purple sweet potato is a delicious and sweet side that is also very fragrant because smells like flowers to me. My husband doesn’t like coconut so he would prefer eating them whole and plain. I have made mashed sweet potatoes for him by substituting coconut milk with milk or soy milk and they’re great coconut-free alternatives.
In this cook once, eat twice recipe, you will make a double batch of potatoes in an Instant Pot on a trivet (affiliate link). Eat some of them whole, as is, right after they’re cooked and then use the other half to make an Okinawan sweet potato mash, which can be served hot or cold. If I don’t have time to mash them up right away, I will refrigerate the cooked potatoes to finish prepping later. Then I will peel, chop, and mash with some coconut milk (or other milk) while reheating on the stove top when I’m ready.
Another way to reheat and serve cooked sweet potatoes is to make a hash. Chop the cooked sweet potatoes and fry them with a little olive oil like breakfast potatoes with a sprinkle of fresh herbs or spices. Then serve the hot and crispy potatoes as a side dish.
Avoid Confusion with Purple Sweet Potatoes, Ube, or Taro
Check the grocery store labels and remember that Okinawan sweet potatoes are also known as Hawaiian sweet potatoes. Uncooked Okinawan sweet potatoes have a smooth beige skin on the outside and are purple on the inside. That’s what you look for when you shopping for this recipe.
Sometimes people refer to Okinawan or Hawaiian sweet potatoes when they’re really about other purple-ish root vegetables (or vice-versa) that are used in Asian recipes. The following are not Hawaiian or Okinawan sweet potatoes:
- Purple sweet potatoes, which are in the same botanical family (Ipomoea batatas) as typical sweet potatoes and Okinawan sweet potatoes. Purple sweet potatoes have a smooth purple skin on the outside and are also called Stokes Purple sweet potato.
- Ube (Dioscorea alata) is botanically a yam, has a brown, rough tree bark-like exterior, and is purple on the inside. Generally, yams are a starchy root vegetable but also refer to sweet potatoes (Ipomoea batatas) for marketing purposes, which is very confusing.
- Taro is also a root vegetable with a rough brown exterior, and is light purple colored on the inside. Taro is not a yam nor a sweet potato but sometimes people confuse taro with ube due to their similar appearances.
Allergy Aware Okinawan Sweet Potatoes
The Okinawan sweet potatoes that are pressured cooked and served plain are free from all top 9 allergens. The mashed potato portion of the recipe is free of peanuts, treenuts (except coconut milk, if using), milk, egg, soy, shellfish, fish, wheat, and sesame as written. If you cannot have coconut milk, substitute with a milk alternative that is safe for you.
Be careful when someone else makes mashed Okinawan sweet potatoes for you. Be sure to check the ingredients as some recipes might top with or mix in nuts, sesame, butter, sour cream, or other allergens.
Instant Pot Okinawan Sweet Potatoes, Two Ways: Pressure Cooked & Mashed
I recommend trying Okinawan sweet potatoes, also known as Hawaiian sweet potatoes. They are so delicious, nutritious, and easy to prepare. My favorite way is to pressure cook them in an Instant Pot however you can also cook them in a pot on your stovetop as well (see notes).
This recipe is a "cook once, eat twice" recipe. Use the Instant Pot to cook all of the sweet potatoes, them serve half of them pressure cooked, plain and simple right out of the pot for your first meal and then make a sweet potato mash for your second meal. Of course, if you like them plain or you like them mashed, serve all of the Okinawan sweet potatoes in the way you prefer.
- 4 pounds Okinawan sweet potatoes (approximately 8-10 medium, 6-8 ounces each)
- 1 cup water
- ¼ cup coconut milk or other alternative milk optional, add 1-2 tablespoon as needed
In a large washing bowl, scrub the sweet potatoes with a vegetable scrubber and rinse until the sweet potatoes are clean.
Place a trivet into the Instant Pot liner and add 1 cup water. Arrange the sweet potatoes on the trivet, larger sweet potatoes and big round ends near the bottom, smaller ones on top, and then lock the lid.
Program the Instant Pot to “pressure cook” (or “manual) for 15 minutes at high pressure.
When the timer chimes, natural pressure release for at least 10 minutes (you can allow it to natural release longer until the rest of dinner is ready), and then release the remaining pressure.
Serve half (or all) of the sweet potatoes.
Make mashed potatoes
If serving the mashed potatoes right away, allow the sweet potatoes to cool to touch, cut the sweet potatoes in half lengthwise and use a spoon to scoop out the flesh and transfer to a medium sized bowl, add ¼ cup of coconut milk (more if needed or if making mashed potatoes using all the cooked sweet potatoes), and stir until the sweet potatoes are well-mixed.
If serving the mashed potatoes later, refrigerate the pressure cooked potatoes in a container after they have cooled down a bit. When you are ready to make them, peel the sweet potatoes with your fingers or a knife and transfer them to a medium sized saucepan. Add the coconut milk (1-2 tablespoons more, as needed) and mix until they’re a mashed consistency while reheating the sweet potatoes on medium low heat (5 minutes).
Stovetop cooking instructions: Wash and scrub the sweet potatoes. Place in a 6-8 quart stock pot and arrange the sweet potatoes as evenly as possible. Add enough water to cover the sweet potatoes and bring the water to a boil and then simmer on medium low heat for 40 minutes until you can poke through them with a fork.
Calorie count is approximately 220 per 6 ounce sweet potato. The actual calories for the mashed sweet potato may vary according to how much coconut (or other) milk you use.
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