White bean soup is a quick fix for a hearty meal

This soup is quick and easy and more than the sum of its parts. And to make it even better, it's inexpensive to prepare.

WHITE-BEAN AND

TOMATO SOUP

1 tablespoon olive oil (optional)

1 medium onion, peeled and chopped (optional)

2 cloves garlic, peeled and chopped (optional)

1 (26-ounce) jar spaghetti sauce

1 (14.5-ounce) can vegetable or chicken broth

1 cup water, plus more if needed

1/2 cup orzo, ditallini, elbows or other small pasta

1 (19-ounce) can cannellini beans (white kidney beans), drained and rinsed

Freshly ground black pepper and salt (if needed)

About 6 tablespoons prepared basil pesto

Toasted slices of baguette (optional)

If you have time, heat the oil in a pot set over medium-low heat, and saute the onion and garlic, stirring frequently, for five minutes. If you are in a hurry, you can skip this step, and omit these ingredients.

Add the spaghetti sauce, broth, water, pasta and beans to the pot, and bring to a simmer. Cover and simmer for 20 minutes, or until pasta is tender. Add pepper and salt to taste, if needed.

To serve: Ladle the soup into warm, shallow soup bowls, and swirl a generous spoonful of pesto in the center. Alternatively, spoon the pesto onto a toasted baguette slice and "float" it in the soup bowl.

Yield: 4 main-course servings

• Marialisa Calta is the author of "Barbarians at the Plate: Taming and Feeding the American Family" (Perigee, 2005). For more information, go to www.marialisacalta.com.