Place the beans in a stockpot with water and salt, cooking them until they are crisp-tender, approximately 2 minutes. Thoroughly drain them in a colander. Next, immerse the colander with the beans in an ice-water bath, making sure the beans are submerged. Drain the beans again, shaking off any excess water.

In the stockpot, warm the oil over low heat; add the beans, garlic, tomatoes, olives, and basil, and toss to combine. Drizzle vinegar over the beans and toss to coat; taste and adjust the seasoning with salt and pepper. Serve hot, warm, or cold.