Firstly you will need to steam or boil sweet potatoes. Rinse 280 grams sweet potatoes (2 medium sized sweet potatoes) very well in water. Then steam them in a pressure cooker or a pan. If cooking in a pressure cooker, then pressure cook for about 4 to 5 whistles with water just about covering the sweet potatoes. You can even peel sweet potatoes first and then steam them.
Let the sweet potatoes become warm or cool down. If you have used a pressure cooker or pan for cooking the sweet potatoes, then drain them very well.
Then roughly chop them.
With a potato masher, mash them very well. There should not be any small chunks of the sweet potatoes.
Add 1 tablespoon all purpose flour (maida). Mix very well and then knead lightly. Gather the dough together.
Now make small or medium sized balls from the dough. Flatten them and place one or half of a pistachio in the center. You can also use sliced almonds or cashews or raisins.
Bring the edges together, seal and form a neat ball. Prepare all the jamuns this way. Keep aside.
preparing sugar syrup
Now take 1 cup sugar or 170 grams sugar and 1/2 cup water in a pan.
Keep the pan on a low flame and stir so that the sugar melts.
Cook the syrup till you get a half-string consistency in it. The syrup should feel sticky and not watery. So you can even cook the sugar syrup till it feels sticky. If the syrup is watery, then the jamuns will break after soaking the syrup.
Switch off the flame and add 1/4 teaspoon cardamom powder. Mix well and keep aside.
The sugar syrup should be hot or warm when you add the jamuns in it.
frying sweet potato gulab jamun
Now heat oil for deep frying in a kadai.
Add a tiny piece of the dough and check the oil temperature. If the dough comes up gradually and steadily, the oil is ready for frying. If it stays at the bottom of the oil, the oil needs to be heated more. If it comes up too quickly, then the oil is too hot for frying. So lower the flame.
Gently place the balls in the oil. Fry at a low to medium temperature. Keep regulating the flame from low to medium as required. Add the jamun for frying as per the pan size. Do not overcrowd the pan.
Only when the jamun have become pale golden, then turn them. Use a wooden spatula while turning them as with a steel slotted spoon, they can break.
Keep on turning & rotating them often for even frying. If you don't turn them regularly, then they will have uneven shades of golden color.
Fry till the jamun turn golden. Then remove with a slotted spoon.
Place them on kitchen paper towels.
soaking sweet potato gulab jamun in sugar syrup
After a few seconds, place them in the sugar syrup.
Shake the pan or with a spoon pour the sugar syrup on top of the jamun.
Cover and keep aside. Fry the remaining jamuns and then keep them in the sugar syrup for soaking.
I kept them in the sugar syrup all the time and did not remove them. But if you see they have become so soft, that they break or crumble, then remove from the sugar syrup and keep aside.
Serve sweet potato gulab jamun garnished with some slices pistachios or almonds.