BruceLee

Grated carrots are great as salad with a vinaigrette and panned-cooked as a side vegetable or in addition in a sauce.
For great amount of onions you can place them unpeeled on a tray in the oven until very soft and froze them for later use, pureed in a sauce or directly mixed with your grains.

You can do mashed carrots. Mixed with potatoes or on its own.