Preheat oven to 400F and line two sheet pans with parchment.
Using a vegetable peeler, peel eggplant if you want – or remove some of the skin in long strips. (Or if you prefer, leave the skin on.) Cut into ½-inch thick bite-sized pieces. Slice the bell pepper into ½-inch wide strips. Cut the tomatoes into ¾-inch wedges. Slice the zucchini the long way and then slice into ½ inch thick half-moons. Slice the onion into ¼-½ inch thick half-moons.
Spread out the veggies on the sheet pan in a single layer (this is why you most likely need two sheet pans).
Drizzle with olive oil and toss, using enough oil to coat generously. Sprinkle with a generous amount of salt and pepper. Toss well.
Roast in the hot oven for 20 minutes; then scatter the whole garlic cloves (peeled) and herbs and mix the veggies. Roast for 20 more minutes, mix again. Turn heat down to 300F and roast for 10-20 more minutes, or until tender and edges begin to caramelize- watch closely here.
Remove from oven, taste, adjust salt and pepper, and drizzle with a little splash of vinegar, carefully mixing.
Use immediately, or cool and refrigerate (or freeze) until ready to use.
