In a small bowl, mix together the yogurt, shallot, minced garlic, sugar, salt, and pepper to create the dressing.

Set the dressing aside.

In a medium bowl, combine the diced tomatoes and sliced cucumbers.

If using a regular cucumber, lightly seed it.

Pour the dressing over the cucumber and tomato mixture.

Add the minced fresh dill.

Toss gently to combine all ingredients.

Let the salad sit for at least 5 minutes for flavors to meld.

Serve the salad chilled, optionally over a bed of fresh greens or alongside broiled fish.