1. Wash the potatoes. Steam them for 20 minutes. Let them cool, then cut into cubes.

2. Rinse the cucumber. Peel it, and cut it in half lengthwise. Scoop out the seeds with a spoon. Cut each half into very thin slices.

3. Rinse and dry the lime. Grate its zest over a large bowl. Squeeze the lime, and pour its juice into the large bowl.

4. Peel the onions and chop them finely.

5. Seed and chop the pepper.

6. In the large bowl, add the onions and the pepper with the sugar, fish sauce, coconut milk, oil, soy sauce, and potato cubes. Mix.

7. Sprinkle with chopped peanuts and chopped cilantro. Serve.