Thinly slice the onion and sauté it in olive oil over low heat. While the onion cooks, roughly chop the bell peppers.

Peel part of the eggplant skin to make it easier to digest. Once the onions are soft, add the bell peppers and sauté together.

After chopping everything, add half a lemon to the pan along with the eggplant, zucchini, chives, and black pepper.

Once everything is sautéed (let each step cook for about 15 minutes), remove the lemon, add the tomatoes, tomato paste, and the juice from the other half of the lemon.

Cook for another 15 minutes. If the sauce is too thick, add a little water. Instead of tomato paste, you can boil tomatoes, peel them, and add them at the end for a more natural option.