Mix yeast with 1 tablespoon lukewarm water and sugar.
Mix flour and salt. Knead with yeast mixture, 30 ml oil, and 100 ml lukewarm water until smooth and soft. Place in a bowl, cover, and let rise in a warm place for 1 hour.
Peel and finely chop onions. Wash parsley, shake dry, pluck leaves, and chop finely. Drain mozzarella and cut into small cubes.
Heat remaining 30 ml oil in a pan over medium heat. Sauté onions for 4 minutes. Add parsley and cook for 2 more minutes. Let cool completely. Mix in mozzarella cubes and season with salt and pepper.
Preheat oven to 175 °C (347 °F). Knead dough again and shape into roughly 20 walnut-sized balls. Roll each ball on a floured surface into a thin circle about 10 cm in diameter.
Place 1 tablespoon filling in the center of each dough circle, leaving roughly a 1 cm edge. Brush edges with water, fold the dough in half to form a crescent, and press the edges with a fork.
Line a baking sheet with baking paper. Bake on the middle rack for 12-15 minutes until golden brown.