• 2 lb. small Italian eggplants (about 4)
• 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt (or 2 tsp. fine sea salt), plus more
• 1½ cups extra-virgin olive oil
• 1 medium onion, chopped
• 4 medium celery ribs, thinly sliced
• ⅓ cup large green Sicilian olives (1¾ oz.), pitted and coarsely chopped
• ⅓ cup Italian capers packed in salt (1¾ oz.), rinsed well
• 2 Tbsp. sugar, plus more
• ⅓ cup white wine vinegar
• 1 (14–15-oz.) can whole tomatoes in juice, drained and chopped