Preheat an oven. All the vegetables should be roughly the same size. Chop and set aside.
Place extra virgin olive oil in a large baking dish, then place in the oven. Once hot, remove and carefully add all chopped vegetables and garlic to the dish. Sprinkle with thinly sliced basil, chopped rosemary, Kosher salt, freshly ground black pepper. Toss to evenly coat.
Return to the oven, then cook, tossing once halfway through, until the vegetables are tender and caramelized. This will take longer if the vegetables are cut into bigger pieces and/or if the pan is overflowing with vegetables.
Drizzle with balsamic vinegar, then stir well. Serve immediately with a pinch of flaky sea salt and additional fresh basil. Enjoy!