Prep the skewers
Soak wooden skewers in water for 30 minutes so they don’t burn.
Preheat oven to 400°F / 200°C if you’ll roast, or heat grill to medium if grilling.
Slice and chop zucchini, peppers, mushrooms, corn, and onions into the sizes listed above. Aim for uniform pieces so everything cooks evenly.
Make the marinade
In a large bowl, whisk together 4 tbsp olive oil, mashed garlic, 2 tsp oregano, 1 tsp salt, and lemon juice.
Marinate in stages: Toss zucchini and peppers in the marinade first, mix well, and transfer to a second bowl. Then coat mushrooms and corn in the remaining marinade, move them to a third bowl. Finally, pour leftover marinade over onion chunks. This staged approach prevents delicate pieces from getting over-marinated and falling apart.
Thread and cook
Thread vegetables onto skewers—alternate colors for a pretty presentation. Be careful: the marinade makes things slippery. If threading corn slices proves too stubborn, place the corn directly on the baking sheet; I do that sometimes.
Arrange skewers on a parchment-lined sheet or grill them directly. Roast in the oven for 25 minutes, turning once, until tender and slightly charred. If grilling, cook over medium heat 10–15 minutes, turning occasionally, until you get char marks and tender veggies.
Finish & serve
Squeeze a little extra lemon over the hot skewers. Serve with lavash and haydari or a bright herb sauce. Eat hot and enjoy the applause.