5 Yukon Gold potatoes (800g), peeled and cut into 1/2 inch cubes
1 large carrot, peeled, quartered lengthwise, then cut into 1/4 inch pieces
1 Japanese or Lebanese cucumber* (100g), thinly sliced
1/4 onion (60g), thinly sliced
1/2 teaspoon salt + 1/2 teaspoon salt
3 tablespoons mayonnaise (preferably Kewpie)
1 tablespoon rice vinegar or lemon juice
1 teaspoon sugar or honey
black pepper to taste
4-5 slices ham (80g), chopped