Score the carrots lengthwise five times using the tip of a sharp knife, a vegetable peeler, or a channeling knife.

Slice into disks about 1/8 inch thick and place in pint jar. Slice enough carrots to fill a pint jar nearly to the neck.

In a small saucepan, combine vinegar, water, sugar, salt, mustard seeds, bay leaves, and cloves. Place over high heat, stir to dissolve sugar and salt, and bring to a boil.

Remove from heat and stir in harissa. Pour over carrots and cover jar.

Place in refrigerator for at least 24 hours before serving.