Preheat the oven to 350 F
Prepare your vegetables. Slice the zucchini and eggplant and potatoes into coins, if the eggplant is too large, cut eggplant coins in half.
Thickly slice the garlic and halve and slice the onion.
Add all the veggies in a large bowl (or you can use the baking pan), season with salt and pepper, a generous pinch of oregano. Add half the oilve oil all over. Mix gently.
In a large baking pan, start roughly stacking the veggies upwards. Mix them together, as you stack.
Place tomatoes in a bowl, crush them with your hand and add them between the vegetables. Add another generous pinch of oregano and season again with salt and freshly ground pepper.
Add the rest of the olive oil, the broth (or water) and stuff the thyme sprigs between the veggies.
Cover with aluminum foil and bake for at least two hours. Remove cover after an hour. Remove from heat, let it sit for 20 min and adjust salt and pepper to taste.