After cutting the aubergines place them in a colander and sprinkle salt over them to be cured and lose some of their water as well as their bitterness. Keep for 30 minutes and then pat dry.
Place a large deep sauteing pan on medium-high heat and add 4 tablespoons of oil. Allow to heat up and a minute later add the aubergines and sauté until nicely browned and softened. Remove from fire to a plate with kitchen paper to absorb the excess oil. Keep aside.
In the same pan add the remaining 2 tablespoons of oil over medium heat and allow to heat up Add the scallions with a pinch of salt and sauté for 3 minutes to soften a bit. Then add the garlic, chillies if using, peppers and celery and continue sauteing for 3 more minutes. Drop in the tomatoes, increase the heat and sauté for 2 more minutes.
Then toss in the olives, capers, vinegar, tomato passata and the honey and toss couple of times. Lower the heat and return the aubergines to the pan, season with the remaining salt and pepper and simmer for 10 minutes with the lid partly on while occasionally stirring.
Remove from fire and allow to cool a bit. Then toss in the oregano and parsley and give it a gently toss. Serve while topping with the feta and the remaining pine nuts while drizzling some more olive oil.