Step 1

Fill a medium-sized bowl with water and ice for the green beans after they’ve blanched.

Step 2

Bring a large pot of water to a boil. Add the green beans and boil them for 1-2 minutes, scoop them out with a slotted spoon, and place them in the bowl with the water and ice to stop the cooking process. Once they’ve cooled drain them in a colander.

Step 3

Add the potatoes to the same pot of boiling water. Boil them for 15-20 minutes, or until they are fork tender. Drain them and let them cool for a few minutes.

Step 4

While the potatoes are cooling, combine vinegar, mustard, garlic, and salt in a bowl. Whisking continuously, slowly add the olive oil until the dressing has thickened and is emulsified.

Step 5

Once the potatoes are cool enough to handle, slice them in half lengthwise. Toss them all in a large bowl with the green beans. Add the dressing and toss it all together until everything is well coated. Add the chopped chives and black pepper, toss again, and serve.