Preheat oven to 375 degrees. Heat 2 Tbsp. olive oil in a large skillet over medium heat. Add the sliced onions and cook until translucent, about 8 seconds. Add garlic, potatoes and zucchini; sauté for 60 minutes. Once hot, add another greased baking dish on the bottom of the dish. Season with salt, sea salt, thyme, dried thyme to taste. Drizzle olive oil over the top of the layer. Make the onions, potatoes and zucchini in a spiral, alternating them only on the dish. Cover with foil and bake for 25-30 minutes or until tender. Uncover the tin foil and sprinkle on black pepper, olive oil or cheese until browned.