- 1/2 medium red onion, chopped (about 1/2 cup)
- 1/2 pound fresh green beans, ends trimmed and blanched until crisp-tender
- 1/2 pound fresh wax beans, ends trimmed and blanched until crisp-tender
- 1 teaspoon salt
- 3/4 cup vegetable oil
- 1 cup plus 2 tablespoons sugar
- 1 1/2 cups red wine vinegar
- 3 peeled whole garlic cloves, plus 1 teaspoon minced garlic
- 12 cups water
- 1/2 cup dried cannellini, navy, or Great Northern beans soaked overnight or 1 1/2 cups canned, drained, and rinsed white beans
- 1/2 cup dried black beans soaked overnight or 1 1/2 cups canned, drained, and rinsed black beans
- 1/2 cup dried red kidney beans soaked overnight or 1 1/2 cups canned, drained, and rinsed red beans
- If using canned beans, go directly to the end of step 4.
- If using dried, soaked beans, put the red beans, black beans, and cannellini in separate saucepans. Add four cups of water and one garlic clove to each pot.
- Over high heat, bring each pot to a boil, reduce the heat to medium-low, and cook until the beans are just tender, about 30 to 45 minutes. Note: These cooking times will vary from one package of dried beans to another.
- Using oven mitts or pot holders, carefully pour the liquid and the beans away from you into a colander set in the sink. Rinse with cool water, and then transfer the beans to a large nonreactive bowl and cover with plastic wrap. Refrigerate, stirring occasionally, until thoroughly chilled, at least 2 hours.
- In a saucepan over high heat, combine the red wine vinegar, sugar, oil, salt, and the minced garlic. Cook until the sugar is dissolved, about 5 minutes. Transfer to a medium, nonreactive bowl, cover with plastic wrap, and refrigerate until thoroughly chilled, at least 2 hours.
- Add the blanched wax beans, green beans, vinegar mixture, and onion to the beans in the large bowl and toss to mix thoroughly. Serve immediately or refrigerate in an airtight container until ready to serve.
- NOTE: This salad is best if made a day in advance and will keep for up to 1 week if refrigerated in an airtight nonreactive container.