Makes 2-1/2 cups.
2 cups plain whole-milk yogurt
1 small seedless (English) cucumber, unpeeled, or 1 regular cucumber, seeded
1 Tbsp plus 1/2 tsp kosher salt
1/2 cup sour cream
1 Tbsp white wine vinegar
Juice of 1 lemon
1 Tbsp olive oil
1 clove garlic, minced or grated
1 tsp minced fresh parsley
1/2 tsp minced fresh dill (or use more parsley, if there's no dill in your garden)
Pinch of freshly ground black pepper
Do ahead: Place yogurt in a cheesecloth-lined sieve and set it over a bowl. Grate the cucumber and toss with 1/2 teaspoon of salt; place in another sieve and set it over another bowl. Place both bowls in the refrigerator for 3 – 4 hours so the yogurt and cucumber can drain.
Transfer thickened yogurt to a large bowl. Squeeze as much liquid from the cucumber as you can, and add to the yogurt. Mix in remaining ingredients, and adjust seasonings to taste.