To make hard-cooked eggs: Gently place the eggs into a pot and add enough water to cover the eggs by 1 inch.
Put the pot on the stove, turn the heat to medium-high, and bring the water to a boil.
As soon as the water boils, turn off the heat, cover the pot and let sit for 10 minutes.
Fill a bowl with cold tap water and add some ice cubes. Using a slotted spoon, gently move the hot eggs into the bowl of ice water and let them cool for 5 minutes
Drain the eggs, crack, and peel.
Put the yogurt, mustard, herbs, and salt in the small bowl and set aside.
Cut the eggs in half lengthwise. Remove the yolks (they’ll pop out if you push the white underneath them) and put them in the bowl with the yogurt and mash until coarse or creamy, whichever you prefer.
Put the whites on a plate. Use a spoon to fill each egg half with the yolk mixture and sprinkle with extra herbs if you like.