Heat 150ml water and milk in a saucepan until lukewarm.
Sift flour into a bowl and stir in yeast, sugar, and salt.
Add the liquid and knead the dough on a floured surface for 10 minutes.
Place dough in an oiled bowl, cover, and let rise for 60 minutes until doubled.
Fry onion and garlic in butter and oil for 10 minutes until softened.
Add chopped sage, cook for 3 minutes, season, and let cool.
Flatten the risen dough and knead in the cooled onion mixture.
Divide into 8 balls, arrange in a circle on a tray, and prove for 45 minutes.
Preheat the oven to 200°C.
Glaze rolls with milk, top with a sage leaf, and bake for 20 minutes.