Imo means sweet potato in Japanese, and in Okinawa it refers to the purple sweet potato, which was the basic staple of the Okinawan diet in the early years of the 20th century and after World War II. The orange-fleshed sweet potatoes we are accustomed to make a fine substitute.
5 medium sweet potatoes (about 3 pounds), peeled and cut into 1-inch cubes
Up to 3⁄4 cup regular or low-fat canned coconut milk
1 teaspoon ground cinnamon, or more as necessary
1⁄2 teaspoon salt, optional
Place the sweet potatoes in a large pot and add enough water so they’re submerged by 1 inch.
Bring to a boil over high heat, then reduce the heat to medium and cook until the potatoes are soft, about 25 minutes.
Drain in a colander set in the sink, then transfer the sweet potatoes to a large bowl.
Add 1⁄2 cup coconut milk and mash with a potato masher or an electric mixer at medium-low speed until creamy, adding more coconut milk to get a smooth, rich puree.
Stir in the cinnamon, as well as the salt, if desired.
