For the Filling:
1 1/2 cups Greek yogurt
1/2 cup finely grated feta cheese
1 tablespoon fresh juice from 1 lemon
1 tablespoon finely minced fresh oregano
1 teaspoon finely minced fresh mint
1 teaspoon finely minced fresh dill
1 teaspoon minced garlic (about 1 medium clove)
Kosher salt and freshly ground black pepper
For the Eggplant Rolls:
2 large eggplants, ends trimmed and cut lengthwise into 1/4-inch slices
1/3 cup extra-virgin olive oil
3 roma tomatoes, stemmed, cored, and cut into 1/4-inch dice
1 English cucumber, seeded and cut into 1/4-inch dice
Kosher salt and freshly ground black pepper