Peel away the outer layers of the garlic bulb skin, leaving the skins of the individual cloves intact. Using a knife, cut off ¼ to a ½ inch of the top of the cloves, exposing individual cloves of garlic. Place the garlic on the center of a parchment-lined cookie sheet.
Arrange the sweet potatoes, carrots and onions around the garlic.
Lightly brush the garlic, sweet potatoes, carrots and onions with oil.
Season with salt and pepper to taste.
Roast for about 30 minutes, or until vegetables are fork tender.
Remove roasted garlic and place in a large stock pot with the vegetable broth. Bring liquid to boil.
Add in all of the roasted vegetables and cumin. Return to boil and then remove from heat.