Ingredients

2 tablespoons olive oil

2 medium onions, chopped

2 pounds carrots, chopped

2 sweet potatoes (1 1/4 pounds total), peeled and chopped

1 piece fresh ginger (2 inches long), peeled and finely chopped (2 tablespoons)

2 cans (14.5 ounces each) reduced-sodium chicken broth

Coarse salt and ground pepper

2 to 3 teaspoons sugar

2 to 3 teaspoons fresh lemon juice (from 1 lemon)

1/4 cup heavy cream (optional)

Preparation

In a large (5-quart) saucepan, heat oil over medium; add onions and cook, stirring occasionally, until translucent, about 5 minutes. Add carrots, sweet potatoes, ginger, broth, and 4 cups water. Season with salt and pepper.

Bring to a boil, reduce to a simmer, and cook until vegetables are tender, about 20 minutes. Working in batches, puree mixture in a blender until smooth; add sugar and lemon juice to taste. Season with salt and pepper, if necessary. (If freezing, proceed to step 3.) Return soup to pan; heat over medium, stirring in cream, if desired.

To freeze: Cool to room temperature. Divide among airtight containers (leaving 1 inch space at top), and freeze up to 3 months. To heat, place container upside down under hot tap water to release block of soup; place in a medium saucepan. Cover, and cook over medium-low, adding water to thin, if necessary. Stir in cream, if desired.