Take the flour in a mixing bowl. Make a well and add the oil.
Mix the flour with the oil , like a crumb. Add salt, nigella seeds and baking soda.
Add water little by little to make a tight dough. Knead for at least 8 to 10 minutes to get a smooth dough. It shoud not spring back immeditely, if a hole is poked with a finger.
Divide the dough into three parts. Take one part and roll it out in a disc shape and as thin as possible, about 1 mm in thickness.
With a knife, cut long strips and then cut diagonally to make diamond shaped nimkis.
Heat oil in a deep vessel and then add the nimkis into the oil when it is hot.
As soon as it touches the oil, it starts to puff up. reduce the temperture immedietaly and slowly flip the nimkis around to evenly cook all of them.
When they are beautifully golden, then them out of the oil and place on a paper towel.
Repeat the process with the entire dough.
Serve nimki hot and the balance, you can store in a air tight container, once it has cooled down.
It will stay well for a week, in case you don't finish before that.