Mix together ½ cup of warm water, 1 teaspoon sugar, and 1 tablespoon yeast. Leave for 5-10 minutes.
Sift the flour in a large bowl. Make a well in the flour and add the dissolved yeast. Add the sugar, butter, egg, lemon peel, and milk.
Mix the dough and remove it from the bowl.
Knead the dough on a floured surface for approx. 10 minutes, adding flour as necessary. Do not make it too stiff.
Let the dough rise in a covered greased bowl (approx. 45-60 minutes) until doubled in bulk.
Punch the dough and divide into two parts. Roll each into a rectangle on a floured board – approx. 16-17 inches by 11-12 inches ( ~40 x 30 cm)
Spread each rectangle with half the poppy seed filling, leaving a 1-inch border on all sides. Roll up each rectangle from the long side like a jelly roll.
Pinch the seams to make the edges secure. Pinch the ends and place them under the roll.
Place the sealed side down on a greased baking sheet.
Cover and let rise until doubled (approx. 45 minutes).
Brush with egg wash or cream.
Slash the top lightly about ¼-inch deep and 2-inches apart all the way along the roll.
Place in a preheated oven at 350 °F/ 175°C. for about 45 to 50 minutes until the rolls become beautifully brown.