Start by chopping all your vegetables into bite-sized pieces. Try to keep them roughly the same size so they cook evenly.
Place everything zucchini, bell peppers, red onion, and mushrooms into a large bowl.
In a small bowl, whisk together: balsamic vinegar, olive oil, minced garlic, Italian herbs, salt and pepper.
Pour this mixture over the vegetables and toss well so everything is nicely coated.
If you have the time, let the vegetables sit for about 30 minutes. It really helps the flavors soak in but if you’re in a rush, don’t worry. They’ll still taste amazing.
Place your grill pan over medium-high heat and let it get nice and hot. If you have a cast-iron grill pan, this is its moment. It gives those gorgeous grill marks and holds heat beautifully but any grill pan will work just fine.
Arrange the vegetables in a single layer on the pan. Don’t overcrowd them you may need to cook in batches.
Let them grill for about 3–4 minutes on each side, turning occasionally with tongs. You’re looking for: tender texture, slight charring, and those irresistible grill marks.This is when the magic happens the balsamic starts to caramelize, and everything smells incredible. If you notice the vegetables sticking or drying out, lightly brush them with a little extra olive oil mixed with balsamic vinegar. A little touch-up goes a long way here.
Not all vegetables cook at the same speed, and that’s okay. Start with onions and bell peppers (they take a bit longer). Add zucchini and mushrooms a few minutes later. This simple trick keeps everything perfectly cooked not too soft, not too firm.
Once everything is grilled to perfection, transfer the vegetables to a serving dish.
Taste and adjust with a little extra salt and pepper if needed.
If you’re using fresh herbs, sprinkle them over the top for a bright, fresh finish.
Serve warm and watch them disappear.