Take...

2 - Onions (medium size) , red, yellow, or white
2 - 3 Celery Ribs
1 lb. Carrots
2 lbs. Potatoes (white)
2 lbs. Sweet Potatoes or Yams
1 tbsp. Rosemary
Olive Oil, extra virgin (optional)

then...

1 Clean and remove the outer skins from the Onions and from the other vegetables (as desired).  Cut into bit e size pieces (+/- 3/4 inch).  Place in a covered glass or ceramic baking dish.  Sprinkle in the Rosemary and mix well.  

2 Roast in a microwave oven on "roast" or in a regular oven set at 350 degrees F. for about 45 minutes or until the vegetables are tender.  Mix the vegetables every 15 minutes.  If you desire the vegetables to be "browned" remove the cover for the last 10-15 minutes and mix every 5 minutes.

Option: Before serving, spray on a little Extra Virgin Olive Oil for flavor and mix well.