Place the green beans in a steamer basket. Add 1 cup of water to the inner pot and place the steamer basket inside. Lock the lid into place. Select Steam and adjust the pressure to High and the time to 0 minutes.
While the pressure builds to cook the beans, make the dressing. In a medium bowl, whisk together all the ingredients.
When the beans are cooked, quick release the pressure. Unlock the lid. Remove the beans; they should be mostly tender but should have a slightly crisp center. Sprinkle them with the salt and let cool for a minute. Add the beans to the dressing and add the tomatoes. Toss well with the dressing and let sit for 2 to 3 minutes, or until barely warm. Add the cilantro, basil, and cashews, and toss gently. Serve immediately.
Notes
Double It: Cook double the amount of the green beans and use the extra in the Italian Tuna and Bean Salad