Sift flour, add salt, sugar, softened butter, egg and knead shortbread dough. Put the dough in the refrigerator for 1.5-2 hours to cool.
Roll out the finished dough on a board sprinkled with flour into a layer about 1 cm thick. Cut out rings from the dough using two molds of different diameters.
Preheat oven to 200'C. Put the rings on a baking sheet and bake until cooked.
Cool the finished rings, cover with a mixture of powdered sugar and lemon juice and sprinkle with poppy seeds.