Trim the zucchini, remove any large spongy seed center if needed, and weigh 300 g. Coarsely grate it.
Warm the garlic-infused oil in a wide skillet over medium heat. Add the zucchini and salt. Cook uncovered for about 8–10 minutes, stirring often, until tender and most visible liquid has evaporated. Reduce the heat if it starts to brown heavily.
Transfer the zucchini to a fine sieve and gently press out excess liquid with a spoon. Spread in a shallow dish and allow to cool, about 15 minutes or until no longer warm.
Stir the cooled zucchini into the thick lactose-free yogurt with chives, parsley, lemon juice and black pepper. For a finer texture, pulse the cooled zucchini and yogurt briefly in a small processor, then stir in the herbs.
Taste with a vegetable and adjust seasoning if needed. Cover and refrigerate promptly until serving. Stir before serving and divide into six equal portions.