Lay the zucchini slices flat onto a paper towel lined tray and sprinkle with ½ teaspoon of salt on all the zucchini slices, both sides. Set aside for 5 to 10 minutes. Pat the zucchini dry from any excess liquid.

Place ¼ cup olive oil in a large saucepan, or enough oil to be ½  inch deep in the pan. Place over medium heat.

Gently place about 6 pieces of zucchini into the pan, making sure that the pieces all lay flat and do not overlap. Fry the zucchini on each side for about 5 minutes until golden brown. Transfer to a baking rack or a paper towel lined tray to drain any excess oil. Continue frying the rest of the zucchini in batches. 

Place the fried zucchini into a mixing bowl. Add salt, pepper, garlic, basil and vinegar. Gently mix until each piece of zucchini is evenly coated. Transfer to an airtight container and refrigerate for at least 5 hours and up to 24 hours.

Serve the concia at room temperature.