- In a bowl, combine all the ingredients and set aside.
- In a small bowl, cover the onion slices with cold water. Add the sugar and salt. Let marinate for 15 minutes. Drain (see note).
- In a non-stick skillet over medium heat, brown the eggplant in 2 tbsp (30 ml) of the oil, until tender, about 4 minutes on each side. Lightly season with salt and pepper. Set aside on a plate.
- In the same skillet over medium heat, soften the zucchini in 1 tbsp (15 ml) of the oil. Lightly season with salt and pepper. Set aside with the eggplant.
- In the same skillet over high heat, brown the cheese in the remaining oil, about 1 minute on each side.
- Spread the lemon mayonnaise onto the buns, as desired. Layer with the lettuce, eggplant, cheese, tomato, zucchini and onion.
We recommend soaking the onion in a salty-sweet solution to remove some of its harshness.