Preheat oven to 250 degrees C and line a baking tray with aluminium foil.
Wash eggplants and prick all over with a knife. Place on baking tray and roast 45 minutes. Let cool.
Peel the eggplants and place in a sieve. Press down to extract their liquid, then chop the flesh.
Boil a saucepan of water and boil the tomatoes for 30 seconds then drain (this makes them easier to peel). Peel and chop the tomatoes, then place them in a frypan with the garlic and a little salt. Cook, stirring, on low heat 20 minutes to make a thick sauce.
Combine the eggplant and tomato sauce in a bowl and add the olive oil, paprika, chilli powder, cumin, parsley and coriander. Season with salt and pepper. Garnish with black olives.