Prepare the Carrots: Wash the carrots thoroughly, peel them, and slice them into thin strips using a knife or slicer.
Salt the Carrots: Place the julienned carrots in a bowl, sprinkle with salt, mix well, and let them sit for about 10 minutes.
Make the Dressing: In a separate bowl, mix the oil dressing ingredients: olive oil, vinegar, whole grain mustard, sugar, and black pepper.
Combine and Store: Add the dressing to the salted carrots, mix well, and store in an airtight container. Let it sit in the refrigerator for 2-3 hours before serving.