Heat the oven to 425 degrees. Using a small knife, score each eggplant half by making several ½-inch-deep slices into the cut side of the flesh, like stripes, from edge to edge without cutting through the skin. Place on a sheet pan, season with salt and pepper all over, drizzle generously with oil and place them cut-side down. Add the chickpeas to the pan, season and drizzle with oil.
Roast the eggplant and chickpeas until the eggplant is tender and golden brown and the chickpeas are crispy, 30 to 35 minutes.
Meanwhile, place the cashews, tahini and crushed red pepper, if using, in the bowl of a food processor. Finely grate the garlic directly into the processor. Finely grate the zest and squeeze the juice from both the lemon and orange, then add the zest and juice to the processor. Add ¼ cup water and purée until smooth, scraping down as needed and adding up to ¼ cup more water as needed to make a smooth spreadable sauce. Season to taste with salt. Transfer to a serving bowl (or transfer to a storage container and refrigerate for up to 2 weeks, if not used right away).
Serve the eggplant by spreading some cashew sauce on a serving platter or individual plates, then arrange the arugula and eggplant over — a metal fish spatula works well to lift the eggplant from the pan. Scatter the chickpeas over, dollop with more cashew sauce and drizzle with olive oil, if desired.
Total Time: 40 minutes
Prep Time: 5 minutes
Cook Time: 35 minutes
