Green Bean Salad with Pickles

1/2 cup pickled veggies, chopped, plus 3 tablespoons brine (I used tiny grocer ABQ's dill pickles)
1/2 small red or white onion, thinly sliced
2 teaspoons kosher salt
1/4 teaspoon black pepper, freshly ground
1 pound bush or pole beans, trimmed and cut into bite-sized pieces
4 ounces feta, crumbled, plus feta brine for seasoning (optional)
2 tablespoons extra-virgin olive oil
Kosher salt, to taste
Freshly ground black pepper, to taste

Bring a large pot of water to a boil. Season boiling water heavily with salt, then add beans. Cook until bright in color and just tender, 3–4 minutes. Drain, then rinse under cold water to stop the cooking and preserve the color. Shake off as much water as possible and pat dry with a kitchen towel.
In a large bowl, stir together pickles, pickle brine, onion, and a few grinds of black pepper. Add green beans to the pickles and stir to combine, then add feta and olive oil and stir once more.
The salad can be stored in an airtight container in the refrigerator for up to 2 days.

Packing for picnic: Store salad in a cooler. Bring salt and pepper and season to taste before serving.