Dissolve yeast and sugar in lukewarm water, let sit 5–10 minutes until foamy.
In a large bowl, combine flour and salt.
Add yeast mixture and oil to the flour mixture and knead into a smooth dough for about 8–10 minutes.
Cover the dough and let it rise in a warm place for about 1 hour, until doubled in size.
Preheat oven to 200°C (390°F) with top and bottom heat.
Divide the risen dough into 4 equal pieces and roll each into an oval shape.
Place cheese and ham in the center of each oval and sprinkle with pepper.
Fold dough edges over the filling and seal well, then place seam-side down on a baking sheet.
Bake hand breads for 20–25 minutes until golden brown and crispy.
While baking, mix sour cream with lemon juice, salt, and pepper, then stir in green onions and chives.
Allow hand breads to cool slightly before serving with the sour cream topping.