Dice the eggplant coarsely and put the cubes in a bowl with salted water (with generous amounts of salt) to get rid of the bitterness.
Chop the onions coarsely with the peppers. Put the onions, peppers and eggplant to fry.
Once fried a bit, pour in the tomatoes from the jar or even better, fresh peeled tomatoes if you have them.
Once thickened, you can add a little diluted flour to thicken further.
Serve with parsley.