Mix the sliced cucumbers and salt together in a strainer. Let the cucumbers drain for 10 minutes. Rinse the salt off the cucumbers with cold water and let the cucumbers drain for 20 more minutes. Pat dry in between layers of paper towels.

Once the cucumbers are dry, add them into a bowl with the chopped red onion, jalapeños, and cilantro; mix well.

In a seperate bowl, to make the dressing, add the Mirim and sugar and stir until the sugar is dissolved. Once the sugar is dissolved, pour the dressing over the salad and mix well to coat all the cucumbers.

Sprinkle the peanuts on top of the salad right before serving.