Dave's Tomato and Cucumber Salad

From Gourmet Magazine September 2003

1/3 cup olive oil
1/4 cup fresh lemon juice
1 tablespoon distilled white vinegar
1 1/4 teaspoons salt
1 teaspoon ground cumin
1/2 teaspoon black pepper
3 3/4 lb vine-ripened or plum tomatoes, cut into 1/3-inch dice (4 cups)
1 lb seedless cucumber (usually plastic-wrapped), cut into 1/3-inch dice (2 1/2 cups)
3/4 cup finely chopped fresh curly parsley (from 1 bunch)
1/4 cup finely chopped onion (preferably sweet onion, such as Vidalia or Walla Walla)

Whisk together oil, lemon juice, vinegar, salt, cumin, and pepper in a medium bowl. Add tomatoes, cucumber, parsley, and onion and stir to combine. Let stand at room temperature 10 minutes before serving.