In a bowl of a stand mixer, place the flour, salt, instant yeast, sugar, onion and garlic powder. Mix using the dough hook attachment.
Add in warm water, milk, vegetable oil and egg. Start mixing using the dough hook attachment on medium low speed until fully combined and the dough starts pulling away from the bowl.
Cover the bowl with kitchen towel and let the dough rise for 30-40 minutes until doubles in size.
Meanwhile, melt the butter in a small pan, once melted, add sage leaves and garlic. Cook for 6-7 minutes until it's aromatic.
Once the dough has risen, divide it into 15 balls, place them on a baking sheet coated with non stick spray. Let them rise for another 20 minutes.
Preheat the oven to 400 degrees F.
Brush the butter, sage and garlic mixture on the dinner rolls. Sprinkle with Parmesan cheese.
Bake in the oven for 20-25 minutes until golden and fully cooked. Brush again with the butter mixture.
Serve warm.