¾ cup walnuts
¼ cup fresh lemon juice (from about 1 lemon)
1 tsp. ground cinnamon
½ tsp. crushed red pepper flakes
¼ cup plus 1 Tbsp. extra-virgin olive oil
4 medium Japanese eggplants (about 1½ lb. total), halved lengthwise, cut crosswise into 2" sections
1 small red onion, very thinly sliced
1½ cups mint leaves, torn if large
2 Tbsp. blind date syrup
Preheat oven to 350°. Toast walnuts on a rimmed baking sheet, tossing occasionally, until fragrant and slightly darker, 8–10 minutes. Let cool, then finely chop; set aside.
Meanwhile, whisk lemon juice, cinnamon, red pepper, and 1 Tbsp. oil in a large bowl.
Heat remaining ¼ cup oil in a large skillet, preferably nonstick, over medium-high. Add eggplant and cook, tossing occasionally, until golden brown and tender, 7–9 minutes. Using a slotted spoon or tongs, transfer eggplant to bowl with dressing, leaving any oil in pan behind; discard oil. Add onion, mint, and three-quarters of reserved walnuts to bowl. Season with salt and toss to combine.
Transfer eggplant salad to a platter. Drizzle with date syrup, then top with remaining walnuts.