Wash the zucchini and pat dry, remove the stem and flower base. Then cut into approx. 1 cm thick slices, with slightly larger zucchini also halve the slices.
Heat 3 tablespoons of olive oil in a large pan and fry the zucchini for about 5 minutes until they are lightly browned. Put the vegetables in a bowl.
Mix the remaining olive oil with the vinegar, the crushed garlic, the parsley, salt, pepper and chili powder. Mix the zucchini with the marinade and let it cool completely.