Stir in the salt, add oil and lukewarm water to the flour and knead the dough. Let it sit while you prepare the stuffing. Wash the Swiss chard, dry with a paper towel, remove the white stems and cut into strips. Finely chop the spring onions and add to the Swiss chard. Season with salt and olive oil.
Divide the dough into 2 equal parts. Roll one part into a circle or rectangle (depending on the pan in which you are baking it) and transfer to a pan that you have previously oiled and sprinkled lightly with corn flour. Spread the Swiss chard and onion on the lower half and cover with the other half of the dough.
Leave 1.5 cm of edges free so that you can connect them and close them with your hands - as if pinching the dough, so that your filling does not come out. Prick the soparnik with a fork a dozen times and bake at 200°C for 30 minutes. In the meantime, prepare a coating of olive oil and pressed garlic and brush it on soparnik as soon as you remove it from the oven. Soparnik is traditionally cut into rhombuses.