Heat 1 inch of olive oil in a deep pot or large skillet over medium-high heat.

Fry eggplant in batches, stirring occasionally, until lightly browned and tender (10-12 minutes).

Drain eggplant on paper towels and season with salt.

Drain all but 1/4 cup of olive oil from the pot and return to medium-high heat.

Add onion, celery, and garlic; season with salt and pepper.

Cook until golden brown (15 minutes).

Add tomato paste and cook, stirring constantly, until lightly caramelized (3 minutes).

Reduce heat to medium.

Add fresh tomato, green olives, raisins, red wine vinegar, sugar, capers, crushed red pepper flakes, and 1/4 cup water.

Cook, stirring frequently, until tomatoes break down (15 minutes).

Turn off heat.

Stir in pine nuts, parsley, lemon juice, and fried eggplant.

Cool to room temperature.

Serve with crostini.