Slice the eggplant and zucchini in approx. 1/2 inch or 1-cm slices and place them on a large tray. Then, sprinkle them with 1 tablespoon of salt, and leave them aside for 15-20 minutes. Pat them dry with a paper towel after.
Cut the peppers in 4, cut the onions, and add all the veggies to a baking tray. Drizzle the olive oil over them and give them a mix.
Roast the veggies at 430°F or 220°C for about 30 minutes.
While the veggies are roasting, make the tahini sauce. Combine 4 tablespoons of tahini paste with 2 tablespoons of lemon juice, 1 minced garlic clove, a pinch of salt, and initially, 2 tablespoons of cold water. Then, give it a mix and continue to add water until you have a smooth sauce. In our case, we used an additional 2 tablespoons of water (for a total of 4 tablespoons in the recipe), but this may vary depending on the tahini paste you use.
Assemble your paninis. This recipe makes 4 large paninis, so on each panini, we put 1/4 of each of the ingredients (zucchini, eggplant, peppers, red onion, feta, and tahini sauce).
Put the tahini in a panini press or grill. We used Tefal’s intelligent grill. For those of you who don’t have a grill, worry not! You can just put them in a large pan on the stove over medium heat and use something heavy to press on them like a big pot, a chef’s press, or another pan. Then flip them after a couple of minutes and press again. I use this method all the time when there’s no panini press available. Enjoy the paninis while warm!