4 cups cubed seedless watermelon, about 1 1/4 pounds

1 pound ripe tomatoes, quartered or cut into sixths

2 to 3 tablespoons fresh lemon juice, to taste

2 tablespoons extra virgin olive oil

Generous 1/2 cup chopped celery (2 ounces)

Salt and freshly ground pepper

Thin celery slices or sticks for garnish

1. Working in batches, purée all of the ingredients except the garnish in a blender for two minutes or longer until frothy and smooth. Taste and adjust seasonings, making sure you have used enough salt and lemon juice for a vivid flavor. Transfer to a bowl, and chill for several hours. Taste and adjust seasonings. Serve, garnishing each bowl with thinly sliced celery or, if serving in glasses, with a thin lengthwise slice of celery stick.

Yield: Four to six regular servings, or 8 to 12 aperitifs.

Advance preparation: You can serve this soup the day after you make it. Leftovers are good for two or three days.

Nutritional information per serving (four servings): 130 calories; 1 gram saturated fat; 1 gram polyunsaturated fat; 5 grams monounsaturated fat; 0 milligrams cholesterol; 17 grams carbohydrates; 2 grams dietary fiber; 19 milligrams sodium (does not include salt to taste); 2 grams protein