Slice the cucumbers into thin rounds, about 1/8 inch thick. Place them in a colander set over a bowl, toss with the kosher salt, and let them sit for 10 minutes. This draws out extra moisture so the brine does not get watered down. Rinse them quickly under cold water and pat dry with a clean kitchen towel.

In a small saucepan over medium heat, combine the red wine vinegar, water, sugar, black pepper, and garlic powder. Stir for about 2 minutes until the sugar dissolves completely. You do not need it to boil, just warm enough to dissolve everything. Remove from heat and let it cool for 5 minutes.

Place the dried cucumber slices in a large mixing bowl or a quart-size jar. Pour the warm brine over the cucumbers and stir or shake gently to coat. Let the mixture cool to room temperature, then cover and refrigerate for at least 1 hour, or up to overnight for a deeper tang.

While the cucumbers chill, toast the walnuts. Add the chopped walnuts to a dry skillet over medium heat and stir constantly for 2 to 3 minutes until they smell nutty and turn golden. Watch them closely because they go from toasted to burnt fast. Spread them on a plate to cool completely.

When you are ready to serve, drain a bit of the brine if the cucumbers are sitting in a lot of liquid. Transfer the cucumbers to a serving bowl, scatter the toasted walnuts and blue cheese crumbles over the top, and add the fresh chives if using. Toss gently once or twice so the cheese does not break up too much. Taste and adjust with a pinch more salt or pepper if needed, then serve cold.