Preheat the oven to 350 degrees. Rub the clove of garlic all over the bottom and sides of a small baking dish. Slice the garlic clove very thinly and set aside until needed.

Heat the butter in a large skillet over medium heat. Add the onion and cook, stirring occasionally, for 15-20 minutes, until tender but not caramelized. Add the sliced garlic and cook, stirring constantly, for 1 minute. Season with sea salt and freshly cracked pepper, to taste.

Spread the onions evenly in the small baking dish.

Layer the tomatoes and zucchini alternately on top of the onion bed so they lean diagonally.

Drizzle the olive oil over the veggies and season with sea salt and freshly cracked black pepper, to taste. Nestle the bay leaf down in one of the crevices.