Step 1

Place 2 pounds small red or Yukon gold potatoes and 1 tablespoon of the kosher salt in a large saucepan. Cover with cool water by 1 inch, then bring to a boil over high heat. Reduce the heat to medium and simmer until the potatoes are cooked through and easily pierced with a knife, 10 to 20 minutes. Meanwhile, trim 12 ounces green beans and cut in half crosswise on a slight diagonal. Halve 1 pint cherry tomatoes (or quarter if large). Coarsely chop 1/2 cup loosely packed fresh parsley leaves.

Step 2

Mince or finely grate 2 garlic cloves and place in a large bowl. Strip the leaves from 2 sprigs fresh rosemary, finely chop (about 1 tablespoon), and add to the bowl. Add 1/3 cup olive oil, 1/4 cup red wine vinegar, 1/4 teaspoon black pepper, and the remaining 1 teaspoon kosher salt. Whisk well to combine and emulsify.

Step 3

When the potatoes are ready, add the green beans and continue to simmer until the green beans are bright green and crisp tender, 1 to 2 minutes. Drain the potatoes and green beans in a colander. Rinse under cold water just until the potatoes are cool enough to handle, about 10 seconds.

Step 4

Halve the potatoes (or quarter if large) and transfer to the bowl of vinaigrette. Add the green beans, tomatoes, and parsley, and gently toss to combine and coat in the vinaigrette. Let sit for 10 minutes to allow for the flavors to meld. Serve warm or at room temperature.