Soaring Onion Prices and 'Acche Din'

What should the government do to prevent the soaring prices of onions? 

Onion prices soar every two-three years to over Rs 100. The reason behind this are those middlemen who loot us as well as the farmers. However, no political leader takes any step against these middlemen as they are hand-in-glove with them. What should the government do to prevent the soaring prices of onions?