Swedish filmjölk can be replaced by yoghurt with some milk added to make it more fluid.
Add baking soda (bicarbonate).
Flour, just enough to make a not too sticky dough (not more!). The less the better. Make a dent with a cup in it before mixing.
The dent is for adding some sweetness...
...like this. You add syrup or honey straight into that dent, but without messing up a cup with goo.
If you have it; I suggest you add some bread seasoning consisting of anise, fennel, cumin
You add approximately one litre of flour or perhaps more, but you actually should add it in steps feeling that it's not too sticky. Preferably too little than too much flour is the trick.
Take an egg-sized piece of dough and flatten it out with your fingers on a floured work space. Let kids join in to do this if you have any around; they will enjoy both making and eating.
Lay the dough into a cast iron frying pan or similar (should have some weight to keep the heat steady) and fry it on 10/12 heat. No butter or oil!
I suggest you pick it a bit with finger tips to make some extra dents in the dough in the beginning, while in the pan.
Keep the process going. You make the next flat bread while one is frying. In this sequence you see the third one being prepared while a second is fried and the first bread is stored in a basket.
Eat while warm with butter melting on and whatever else you may prefer. Makes about 14 cakes; 190 Cal each if that's of any interest.