Step 1

Place the potatoes and one teaspoon of salt in a pot and cover with cold water by by an inch. Bring to a boil and cook potatoes for 15 minutes or until tender when poked with a fork. Drain potatoes in a colander. Transfer them to a large mixing bowl and let them cool for 15 minutes or so.

Step 2

Blanch sliced carrots in salted boiling water for 2 minutes to soften them a bit. Drain carrots in a colander and run under cold water over them to stop the cooking process. Let them sit in the colander for a few minutes, until dry.

Step 3

Whisk all the dressing ingredients: Mayo, vinegar, mustard, salt, sugar, and pepper.

Step 4

Mash the potatoes with a fork, leaving some small chunks for texture. Add carrots, cucumbers, scallions and half the dressing to the bowl. Toss gently to combine. Add more dressing, tossing, until you get the desired consistency. You may not need all the dressing. Correct the seasoning with  salt and pepper, to taste. Chill until ready to serve. The salad can be made up to a day ahead and stored in the fridge.