1 teaspoon freshly ground black pepper, or to taste
Parchment paper for lining the baking sheet (for slices only)
Preheat the oven to 400 degrees F.
To roast eggplant cubes: Stem the eggplants. Cut each lengthwise into 4 pieces. Cut each quarter crosswise into pieces about 1 ½ to 2 inches thick. In a bowl, combine the eggplant cubes with the olive oil, balsamic vinegar, and salt and pepper to taste and toss well to coat. Place in a single layer on a large baking sheet and roast 20 minutes, until the pieces are golden brown. Remove and let cool on the baking sheet. Store in a covered container in the refrigerator for up to 24 hours.
To roast eggplant slices: Stem the eggplants, then cut them crosswise into ½ -inch-thick slices. Mix the olive oil, vinegar, salt, and pepper in a small bowl. Line a large baking sheet with parchment paper. Brush the paper with some of the seasoned oil, then arrange the slices on it in one layer; brush the slices with the remaining seasoned oil. Roast for 20 minutes. (There is no need to turn the slices.) Let cool on a rack. Store as directed for roasted eggplant cubes.
